nb/intel/haswell: Fully handle GDXCBAR and EDRAMBAR

GDXCBAR and EDRAMBAR are accounted for when reporting resources to the
allocator, but they are not present in the DSDT. In addition, coreboot
does not enable either range, but MRC.bin sets up GDXCBAR and does not
disable it afterwards. Not reporting GDXCBAR in the DSDT can result in
resource conflicts, and not enabling EDRAMBAR can cause issues on CPUs
with eDRAM.

Enable both GDXCBAR and EDRAMBAR in coreboot code, and report these
ranges in the DSDT. This matches what Broadwell does. The value for
the `GDXC_BASE_ADDRESS` macro matches what MRC.bin programs as well.

Tested on Asrock B85M Pro4 with an i7-4770S (no eDRAM):
- Still boots
- EDRAMBAR is now enabled with base address of 0xfed80000
- GDXCBAR is still mapped with base address of 0xfed84000

Change-Id: I5538873b30e3d02053e4ba125528d32453ef6572
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55480
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
diff --git a/src/northbridge/intel/haswell/early_init.c b/src/northbridge/intel/haswell/early_init.c
index 15a0b1b..13c2dcd 100644
--- a/src/northbridge/intel/haswell/early_init.c
+++ b/src/northbridge/intel/haswell/early_init.c
@@ -21,6 +21,9 @@
 	pci_write_config32(HOST_BRIDGE, DMIBAR, CONFIG_FIXED_DMIBAR_MMIO_BASE | 1);
 	pci_write_config32(HOST_BRIDGE, DMIBAR + 4, 0);
 
+	mchbar_write32(EDRAMBAR, EDRAM_BASE_ADDRESS | 1);
+	mchbar_write32(GDXCBAR, GDXC_BASE_ADDRESS | 1);
+
 	/* Set C0000-FFFFF to access RAM on both reads and writes */
 	pci_write_config8(HOST_BRIDGE, PAM0, 0x30);
 	pci_write_config8(HOST_BRIDGE, PAM1, 0x33);