msm: drm: uapi: Add PCC flag to specify PCC evaluation position

A new position control register has been added to the DSPP PCC
on Lahaina. This register controls whether PCC is invoked
before or after GAMUT mapping.

Introduce a PCC UAPI flag to indicate if PCC should be placed
before the GAMUT block. By default PCC will be placed after
GAMUT.

Change-Id: I0bcc35e0ce7f87c7fa29922a6a485abe479d893a
Signed-off-by: Christopher Braga <cbraga@codeaurora.org>

include/uapi/display/drm/msm_drm_pp.h

@@ -31,9 +31,12 @@ struct drm_msm_pcc_coeff {
 	__u32 rgb;
 };
 
+#define PCC_BEFORE (1 << 0)
+
 /**
  * struct drm_msm_pcc - pcc feature structure
- * @flags: for customizing operations
+ * @flags: for customizing operations. Values can be
+ *         - PCC_BEFORE: Operate PCC using a 'before' arrangement
  * @r: red coefficients.
  * @g: green coefficients.
  * @b: blue coefficients.