kernel: move DRM_DEBUG_* symbols to generic config

While working on a new target (meson), the kernel build failed due to
missing DRM_DEBUG_MM_SELFTEST symbol. This can potentially happen on all
targets that enable DRM drivers in the kernel config or via kmod
packages, so add it to the generic config and remove it from x86
subtarget configs, together with DRM_DEBUG_MM.

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>

target/linux/generic/config-4.14

@@ -1140,6 +1140,8 @@ CONFIG_DQL=y
 # CONFIG_DRM_BOCHS is not set
 # CONFIG_DRM_CIRRUS_QEMU is not set
 # CONFIG_DRM_DP_AUX_CHARDEV is not set
+# CONFIG_DRM_DEBUG_MM is not set
+# CONFIG_DRM_DEBUG_MM_SELFTEST is not set
 # CONFIG_DRM_DUMB_VGA_DAC is not set
 # CONFIG_DRM_ETNAVIV is not set
 # CONFIG_DRM_EXYNOS is not set

target/linux/x86/generic/config-default

@@ -72,8 +72,6 @@ CONFIG_DRM_AMDGPU=y
 # CONFIG_DRM_AMD_ACP is not set
 CONFIG_DRM_BOCHS=y
 CONFIG_DRM_BRIDGE=y
-# CONFIG_DRM_DEBUG_MM is not set
-# CONFIG_DRM_DEBUG_MM_SELFTEST is not set
 CONFIG_DRM_FBDEV_EMULATION=y
 CONFIG_DRM_FBDEV_OVERALLOC=100
 # CONFIG_DRM_GMA500 is not set

target/linux/x86/legacy/config-default

@@ -58,8 +58,6 @@ CONFIG_DRM_AMDGPU=y
 # CONFIG_DRM_AMD_ACP is not set
 CONFIG_DRM_BOCHS=y
 CONFIG_DRM_BRIDGE=y
-# CONFIG_DRM_DEBUG_MM is not set
-# CONFIG_DRM_DEBUG_MM_SELFTEST is not set
 CONFIG_DRM_FBDEV_EMULATION=y
 CONFIG_DRM_FBDEV_OVERALLOC=100
 # CONFIG_DRM_GMA500 is not set