intel/i945: Fix "always false" statement

Also replace magic number with already existing #define

Change-Id: I64d22aca185bf43ff0ac126584b41920182a1112
Found-by: Coverity Scan
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/6990
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Idwer Vollering <vidwer@gmail.com>
diff --git a/src/northbridge/intel/i945/early_init.c b/src/northbridge/intel/i945/early_init.c
index 08ce10b..a134683 100644
--- a/src/northbridge/intel/i945/early_init.c
+++ b/src/northbridge/intel/i945/early_init.c
@@ -502,7 +502,7 @@
 	DMIBAR32(0x338) = DMIBAR32(0x334);
 	DMIBAR32(0x338) = DMIBAR32(0x338);
 
-	if (i945_silicon_revision() == 1 && ((MCHBAR8(0xe08) & (1 << 5)) == 1)) {
+	if (i945_silicon_revision() == 1 && (MCHBAR8(DFT_STRAP1) & (1 << 5))) {
 		if ((MCHBAR32(0x214) & 0xf) != 0x3) {
 			printk(BIOS_INFO, "DMI link requires A1 stepping workaround. Rebooting.\n");
 			reg32 = DMIBAR32(0x224);