AGESA boards: Rename files containing OEM configuration

There are other things besides PCIe port configuration that
require board specific hooks.

Change-Id: I0923651487b9ed5f6f7569ce08e02d993fa5f976
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/14527
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/mainboard/biostar/am1ml/Makefile.inc

@@ -15,8 +15,8 @@
 
 romstage-y += buildOpts.c
 romstage-y += BiosCallOuts.c
-romstage-y += PlatformGnbPcie.c
+romstage-y += OemCustomize.c
 
 ramstage-y += buildOpts.c
 ramstage-y += BiosCallOuts.c
-ramstage-y += PlatformGnbPcie.c
+ramstage-y += OemCustomize.c