We add x11 into REQUIRED_DISTRO_FEATURES because one of the dependency
gtkmm4 require x11, now, gtkmm4 don't require x11, so remove x11 from
REQUIRED_DISTRO_FEATURES
Signed-off-by: Changqing Li <changqing.li@windriver.com>
Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>