Remove drivers that we do not want to build from gpu/drm/Makefile

--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -30,22 +30,14 @@ CFLAGS_drm_trace_points.o := -I$(src)
 obj-$(CONFIG_COMPAT_DRM)	+= drm.o
 obj-$(CONFIG_COMPAT_DRM_USB)   += drm_usb.o
 obj-$(CONFIG_COMPAT_DRM_TTM)	+= ttm/
-obj-$(CONFIG_COMPAT_DRM_TDFX)	+= tdfx/
-obj-$(CONFIG_COMPAT_DRM_R128)	+= r128/
 obj-$(CONFIG_COMPAT_DRM_RADEON)+= radeon/
-obj-$(CONFIG_COMPAT_DRM_MGA)	+= mga/
 obj-$(CONFIG_COMPAT_DRM_I810)	+= i810/
 obj-$(CONFIG_COMPAT_DRM_I915)  += i915/
 obj-$(CONFIG_COMPAT_DRM_MGAG200) += mgag200/
 obj-$(CONFIG_COMPAT_DRM_CIRRUS_QEMU) += cirrus/
-obj-$(CONFIG_COMPAT_DRM_SIS)   += sis/
-obj-$(CONFIG_COMPAT_DRM_SAVAGE)+= savage/
 obj-$(CONFIG_COMPAT_DRM_VMWGFX)+= vmwgfx/
 obj-$(CONFIG_COMPAT_DRM_VIA)	+=via/
 obj-$(CONFIG_COMPAT_DRM_NOUVEAU) +=nouveau/
-obj-$(CONFIG_COMPAT_DRM_EXYNOS) +=exynos/
 obj-$(CONFIG_COMPAT_DRM_GMA500) += gma500/
-obj-$(CONFIG_COMPAT_DRM_UDL) += udl/
 obj-$(CONFIG_COMPAT_DRM_AST) += ast/
-obj-$(CONFIG_COMPAT_DRM_SHMOBILE) +=shmobile/
 obj-y			+= i2c/
