MTRR: Mark all prefetchable resources as WRCOMB.

Change-Id: I2ecfd9733b65b6160bc2232d22db7b16692a847f
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/5149
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/cpu/x86/mtrr/mtrr.c

@@ -178,9 +178,8 @@ static struct memranges *get_physical_address_space(void)
 		                        MTRR_TYPE_UNCACHEABLE);
 
 		/* Handle any write combining resources. Only prefetchable
-		 * resources with the IORESOURCE_WRCOMB flag are appropriate
-		 * for this MTRR type. */
-		match = IORESOURCE_PREFETCH | IORESOURCE_WRCOMB;
+		 * resources are appropriate for this MTRR type. */
+		match = IORESOURCE_PREFETCH;
 		mask |= match;
 		memranges_add_resources(addr_space, mask, match,
 		                        MTRR_TYPE_WRCOMB);