mediatek: limit recent changes to MTK8173

Previous change introduced a regression to CTS tests on other mediatek
board then MTK8173. This CL fixes this by switching to relying on
MTK_MT8173 compile define.

BUG=b:305347887
TEST=android.mediav2.cts.CodecEncoderSurfaceTest

Cq-Depend: chromium:4887244
Change-Id: I30f814222423e1b77d25c3256e9fcb0319c6339f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/minigbm/+/4946471
Reviewed-by: Hirokazu Honda <[email protected]>
Tested-by: BartÅ‚omiej Grzesik <[email protected]>
Commit-Queue: Kazuhiro Inaba <[email protected]>
1 file changed