Description of problem:
As part of VM pool testing we create pool from template and update his size.
The update failed via REST API.  
Response from REST: 
Cannot edit VM-Pool. Sound device is not supported on 'ppc64' architecture.

The sound device is not supported in PPC see bz 1253261

Version-Release number of selected component (if applicable):
RHEVM Version: 3.6.1.3-0.1.el6 
vdsm-4.17.13-1.el7ev
libvirt-1.2.17-13.el7_2.2

How reproducible:
All the time


Steps to Reproduce (All via REST):
PPC setup.
1. Create VM pool from template with 2 VMs
2. Update VM pool size to 3 (Increase with 1 VM)

Additional info:
Update size request:
2015-12-15 11:15:04,593 - MainThread - vmpools - DEBUG - PUT request content is --  url:/api/vmpools/00203195-654c-4fa9-8aff-af20f655f578 body:<vmpool id="00203195-654c-4fa9-8aff-af20f655f578">
    <size>3</size>
    <cluster href="/api/clusters/2d5db03a-7a36-490b-84b6-a0722411e588" id="2d5db03a-7a36-490b-84b6-a0722411e588">
        <actions>
            <link href="/api/clusters/2d5db03a-7a36-490b-84b6-a0722411e588/resetemulatedmachine" rel="resetemulatedmachine"/>
        </actions>
        <name>golden_env_mixed_1</name>
        <link href="/api/clusters/2d5db03a-7a36-490b-84b6-a0722411e588/networks" rel="networks"/>
        <link href="/api/clusters/2d5db03a-7a36-490b-84b6-a0722411e588/permissions" rel="permissions"/>
        <link href="/api/clusters/2d5db03a-7a36-490b-84b6-a0722411e588/glustervolumes" rel="glustervolumes"/>
        <link href="/api/clusters/2d5db03a-7a36-490b-84b6-a0722411e588/glusterhooks" rel="glusterhooks"/>
        <link href="/api/clusters/2d5db03a-7a36-490b-84b6-a0722411e588/affinitygroups" rel="affinitygroups"/>
        <link href="/api/clusters/2d5db03a-7a36-490b-84b6-a0722411e588/cpuprofiles" rel="cpuprofiles"/>
        <cpu id="IBM POWER 8">
            <architecture>PPC64</architecture>
        </cpu>
        <data_center href="/api/datacenters/f87e6f1e-f32d-4607-b8ef-2ccc405e1c2a" id="f87e6f1e-f32d-4607-b8ef-2ccc405e1c2a"/>
        <memory_policy>
            <overcommit percent="200"/>
            <transparent_hugepages>
                <enabled>true</enabled>
            </transparent_hugepages>
        </memory_policy>
        <scheduling_policy href="/api/schedulingpolicies/b4ed2332-a7ac-4d5f-9596-99a439cb2812" id="b4ed2332-a7ac-4d5f-9596-99a439cb2812">
            <name>none</name>
            <policy>none</policy>
        </scheduling_policy>
        <version major="3" minor="6"/>
        <error_handling>
            <on_error>migrate</on_error>
        </error_handling>
        <virt_service>true</virt_service>
        <gluster_service>false</gluster_service>
        <threads_as_cores>false</threads_as_cores>
        <tunnel_migration>false</tunnel_migration>
        <trusted_service>false</trusted_service>
        <ha_reservation>false</ha_reservation>
        <optional_reason>false</optional_reason>
        <maintenance_reason_required>false</maintenance_reason_required>
        <ballooning_enabled>false</ballooning_enabled>
        <ksm>
            <enabled>false</enabled>
            <merge_across_nodes>true</merge_across_nodes>
        </ksm>
        <required_rng_sources/>
        <fencing_policy>
            <enabled>true</enabled>
            <skip_if_sd_active>
                <enabled>false</enabled>
            </skip_if_sd_active>
            <skip_if_connectivity_broken>
                <enabled>false</enabled>
                <threshold>50</threshold>
            </skip_if_connectivity_broken>
        </fencing_policy>
        <migration>
            <auto_converge>inherit</auto_converge>
            <compressed>inherit</compressed>
        </migration>
    </cluster>
    <template id="e22d3cbf-43d1-4341-a3dc-e5ac0cebd26d"/>
</vmpool>