drm: add msm compressed format modifiers

Qualcomm Snapdragon chipsets uses compressed format
to optimize BW across multiple IP's. This change adds
needed modifier support in drm for a simple 4x4 tile
based compressed variants of base formats.

Changes in v3:
- Removed duplicate entry for DRM_FORMAT_MOD_QCOM_COMPRESSED (Rob Clark)
Changes in v4:
- Remove all modifiers aside from COMPRESSED, this includes tiled and
  10-bit
Signed-off-by: Jeykumar Sankaran <jsanka@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

include/uapi/drm/drm_fourcc.h

@@ -299,6 +299,19 @@ extern "C" {
  */
 #define DRM_FORMAT_MOD_SAMSUNG_64_32_TILE	fourcc_mod_code(SAMSUNG, 1)
 
+/*
+ * Qualcomm Compressed Format
+ *
+ * Refers to a compressed variant of the base format that is compressed.
+ * Implementation may be platform and base-format specific.
+ *
+ * Each macrotile consists of m x n (mostly 4 x 4) tiles.
+ * Pixel data pitch/stride is aligned with macrotile width.
+ * Pixel data height is aligned with macrotile height.
+ * Entire pixel data buffer is aligned with 4k(bytes).
+ */
+#define DRM_FORMAT_MOD_QCOM_COMPRESSED	fourcc_mod_code(QCOM, 1)
+
 /* Vivante framebuffer modifiers */
 
 /*