drm/i915/gvt: Fix two CFL MMIO handling caused by regression.

D_CFL was incorrectly removed for:
GAMT_CHKN_BIT_REG
GEN9_CTX_PREEMPT_REG

V2: Update commit message.
V3: Rebase and split Fixes and mis-handled MMIO.

Fixes: 43226e6f (drm/i915/gvt: replaced register address with name)
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Colin Xu <colin.xu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200601030638.16002-1-colin.xu@intel.com

drivers/gpu/drm/i915/gvt/handlers.c

@@ -3132,8 +3132,8 @@ static int init_skl_mmio_info(struct intel_gvt *gvt)
 	MMIO_DFH(GEN9_WM_CHICKEN3, D_SKL_PLUS, F_MODE_MASK | F_CMD_ACCESS,
 		 NULL, NULL);
 
-	MMIO_D(GAMT_CHKN_BIT_REG, D_KBL);
-	MMIO_D(GEN9_CTX_PREEMPT_REG, D_KBL | D_SKL);
+	MMIO_D(GAMT_CHKN_BIT_REG, D_KBL | D_CFL);
+	MMIO_D(GEN9_CTX_PREEMPT_REG, D_SKL_PLUS);
 
 	return 0;
 }