drm_hwcomposer: Update the platform precompiler guards

Rename the guards in the platform headers to match their
filename. This wasn't done in the previous commits so the
diff remained clean.

BUG=b/28117135
TEST=compiles

Change-Id: Ie495bd8e00784da1d48f200c6981f23448b7c6d2
Signed-off-by: Sean Paul <seanpaul@chromium.org>
3 files changed