drm/exynos: fixed page align and code clean.

1M section, 64k page count also should be rounded up so this patch
rounds up them and caculates page count of them properly and also
checks memory flags from user.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

include/drm/exynos_drm.h

@@ -96,7 +96,8 @@ struct drm_exynos_plane_set_zpos {
 /* memory type definitions. */
 enum e_drm_exynos_gem_mem_type {
 	/* Physically Non-Continuous memory. */
-	EXYNOS_BO_NONCONTIG	= 1 << 0
+	EXYNOS_BO_NONCONTIG	= 1 << 0,
+	EXYNOS_BO_MASK		= EXYNOS_BO_NONCONTIG
 };
 
 #define DRM_EXYNOS_GEM_CREATE		0x00