ARM: EXYNOS: add platform device for core DRM subsystem

Add platform device for Exynos DRM core. This device is used
for creating DRM user-space device and allocating memory for
display buffers.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig
index e81c35f..8bc89f2 100644
--- a/arch/arm/mach-exynos/Kconfig
+++ b/arch/arm/mach-exynos/Kconfig
@@ -80,6 +80,11 @@
 	help
 	  Compile in platform device definitions for AHCI
 
+config EXYNOS_DEV_DRM
+	bool
+	help
+	  Compile in platform device definitions for core DRM device
+
 config EXYNOS4_SETUP_FIMD0
 	bool
 	help