intel CAR: Fix DCACHE_RAM_BASE for old sockets

When using fixed MTRRs for CAR setup, CONFIG_DCACHE_RAM_BASE is ignored
and was not correctly set on affected sockets and boards. It was still
referenced in romstage linker script. This was discovered by clang builds
failing for cases where DCACHE_RAM_BASE = 0, while gcc builds passed.

The actual DCACHE_RAM_BASE programming is base = 0xd0000 - size, as taken
from intel/cpu/cache_as_ram.inc.

Change-Id: Ied5ab2e9683f12990f1aad48ee15eaf91133121c
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/7887
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>

src/cpu/intel/socket_mPGA479M/Kconfig

@@ -6,3 +6,15 @@ config CPU_INTEL_SOCKET_MPGA479M
 	select CPU_INTEL_MODEL_F2X
 	select MMX
 	select SSE
+
+if CPU_INTEL_SOCKET_MPGA479M
+
+config DCACHE_RAM_BASE
+	hex
+	default 0xc8000
+
+config DCACHE_RAM_SIZE
+	hex
+	default 0x08000
+
+endif