gstreamer1.0-omx: drop custom cflags
This is not need any more to build with gstreamer 1.18
GSTREAMER_1_0_OMX_TARGET_rpi = "rpi"
GSTREAMER_1_0_OMX_CORE_NAME_rpi = "${libdir}/libopenmaxil.so"
-EXTRA_OEMESON_append_rpi = " -Dheader_path=${STAGING_DIR_TARGET}/usr/include"
-CFLAGS_append_rpi = " \
- -I${STAGING_DIR_TARGET}/usr/include/IL \
- -I${STAGING_DIR_TARGET}/usr/include/interface/vcos/pthreads \
- -I${STAGING_DIR_TARGET}/usr/include/interface/vmcs_host/linux \
-"
+EXTRA_OEMESON_append_rpi = " -Dheader_path=${STAGING_DIR_TARGET}/usr/include/IL"
