nb/intel/ironlake: Remove unused constant

Change-Id: I0a32295e72270cde2e9bd2f8f00358b47ffd3e33
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48562
Reviewed-by: Christian Walter <christian.walter@9elements.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/northbridge/intel/ironlake/raminit.c

@@ -330,8 +330,6 @@ static u32 get_580(int channel, u8 addr)
 	return ret;
 }
 
-const int cached_config = 0;
-
 #define NUM_CHANNELS 2
 #define NUM_SLOTS 2
 #define NUM_RANKS 2