amd/fam10: Fix pstate configuration

Testing for msr.hi | PS_EN_MASK doesn't make sense.

Change-Id: If3305e4255f227be4bb7a5496a625ef2a50a5808
Found-by: Coverity Scan
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: http://review.coreboot.org/7578
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Tested-by: build bot (Jenkins)

src/cpu/amd/model_10xxx/fidvid.c

@@ -196,7 +196,7 @@ static u8 setPStateMaxVal( device_t dev ) {
 	   msr.hi |= PS_EN_MASK ;
 	     wrmsr(PS_REG_BASE + i, msr);
 	 }
-         if (msr.hi | PS_EN_MASK) {
+         if (msr.hi & PS_EN_MASK) {
 	   maxpstate = i;
 	 }
       }