Don't use V4L2_PIX_FMT_ARGB32 if its not defined

Fixes the build for targets using headers from pre 3.17 kernels
Test:  lunch bullhead-userdebug & m -j android.hardware.automotive.evs@1.0-sample

Change-Id: Ic830d6c89b733d6cd6aa83c1b294731123f7506c
1 file changed