msm: kgsl: Add support for the preamble context flag

Userspace will set a flag in the context if preambles are in use. If
they are, we can safely skip save and restore commands for the
context. GMEM save/restore is still required.  To improve performance,
preamble commands are skipped when the context hasn't changed since
the last issueibcmds.

Change-Id: I21bb8996d62651122dbebcf7a79543679109e1f9
Signed-off-by: Vijay Krishnamoorthy <adivarah@codeaurora.org>
diff --git a/include/linux/msm_kgsl.h b/include/linux/msm_kgsl.h
index 5e37c02..9eb6dda 100644
--- a/include/linux/msm_kgsl.h
+++ b/include/linux/msm_kgsl.h
@@ -9,6 +9,7 @@
 #define KGSL_CONTEXT_NO_GMEM_ALLOC	2
 #define KGSL_CONTEXT_SUBMIT_IB_LIST	4
 #define KGSL_CONTEXT_CTX_SWITCH	8
+#define KGSL_CONTEXT_PREAMBLE	16
 
 /* Memory allocayion flags */
 #define KGSL_MEMFLAGS_GPUREADONLY	0x01000000