Description of problem:

Version-Release number of selected component (if applicable):
pkgconf-1.2.1-1.fc26.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Install lirc-devel + deps
2. Invoke pkg-config and watch actual actual result:

# pkg-config --cflags  lirc-driver
-fpic -DPLUGINDOCS="/usr/share/doc/lirc/plugindocs"


Expected results:
As in f25 (pkgconfig-0.29.1-1):

# pkg-config --cflags  lirc-driver
-fpic -DPLUGINDOCS=\"/usr/share/doc/lirc/plugindocs\"

                    
Additional info:

Obviously, pkg-conf doesn't parse the lirc-driver.pc the same way as pkg-config. Relevant parts of this below, note how PLUGINDOCS is quoted.
-------------------------------------------------------

Name: lirc

PACKAGE_TARNAME=lirc
prefix=/usr
docdir=${prefix}/share/doc/${PACKAGE_TARNAME}

Cflags: -I${includedir} -fpic -DPLUGINDOCS='"${docdir}/plugindocs"'

---------------------------------------------------------