branding: remove ovirt suffix from files

without theme specific suffix, it is easier to diff between two
different packages.

we have the theme name at the directory name, having this within files
as well does not have large benefit.

Change-Id: I0c13c5d279dd6052b9a3d771edab04c1a30723ff
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>