soc/intel/broadwell/gma: don't unconditionally remap all GPU PCI IDs

This fixes the case where a Broadwell CPU is combined with an AMD or
NVIDIA GPU would result in using the Broadwell GPU VBIOS file from CBFS
for the discrete GPU too. A further improvement would be to use a list
of the Intel iGPU PCI IDs like it is done in the Skylake code.

TEST=None

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I3eb50cb9a0539255d50e5cd8163f10c3a062cc4d
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73611
Reviewed-by: Martin Roth <martin.roth@amd.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>

src/soc/intel/broadwell/gma.c

@@ -240,7 +240,10 @@ static const struct reg_script broadwell_late_init_script[] = {
 
 u32 map_oprom_vendev(u32 vendev)
 {
-	return SA_IGD_OPROM_VENDEV;
+	if (vendev >> 16 == PCI_VID_INTEL)
+		return SA_IGD_OPROM_VENDEV;
+	else
+		return vendev;
 }
 
 static struct resource *gtt_res = NULL;