Fix G33 GTT stolen mem range

G33 GTT table lives in seperate stolen mem with
graphics data stolen mem.

src/i830_driver.c

@@ -483,6 +483,9 @@ I830DetectMemory(ScrnInfoPtr pScrn)
    range = gtt_size + 4;
 
    if (IS_I85X(pI830) || IS_I865G(pI830) || IS_I9XX(pI830)) {
+      /* G33 has seperate GTT stolen mem */
+      if (IS_G33CLASS(pI830))
+	  range = 0;
       switch (gmch_ctrl & I830_GMCH_GMS_MASK) {
       case I855_GMCH_GMS_STOLEN_1M:
 	 memsize = MB(1) - KB(range);