Description of problem:
rhnKickstartTimezone table contains several invalid time zones for rhel_6
install type (quite possible also for rhel_5).

Choosing this invalid timezone in Satellite's webui will result into
anaconda falling back to America/New_York (i.e. ignoring the invalid
timezone definition coming from Satellite).

The timezones for each available install type (rhel_5, rhel_6, ...) need
to actually match what that particular system / distro supports.

Version-Release number of selected component (if applicable):
spacewalk-schema-1.7.55-32.el6sat.noarch
satellite-schema-5.5.0.15-1.el6sat.noarch

How reproducible:
Always

Steps to Reproduce:
1. Create a kickstart profile for RHEL-5, RHEL-6, ...
2. Navigate to the following webui app: rhn/kickstart/Locale.do?ksid=...
and check whether the timezones presented match locales supported
by that particular system (RHEL-5, RHEL-6, ...)
  
Actual results:
RHN Satellite contains invalid timezone definitions for kickstarting.

Expected results:
Timezone definitions for kickstart in RHN Satellite are valid.

Additional info:
N/A