intel-agp: Fix i830 mask variable that changed with G33 support

The mask on i830 should be 0x70 always, later chips 0xF0 should be okay.

Signed-off-by: Dave Airlie <airlied@linux.ie>
Acked-by: Zhenyu Wang <zhenyu.z.wang@intel.com>
Cc: Michael Haas <laga@laga.ath.cx>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/agp/intel-agp.c

@@ -511,7 +511,7 @@ static void intel_i830_init_gtt_entries(void)
 		 */
 		if (IS_G33)
 			size = 0;
-		switch (gmch_ctrl & I830_GMCH_GMS_MASK) {
+		switch (gmch_ctrl & I855_GMCH_GMS_MASK) {
 		case I855_GMCH_GMS_STOLEN_1M:
 			gtt_entries = MB(1) - KB(size);
 			break;