video: tegra: nvmap: Add flag to skip cache cleaning at alloc

For bigger buffer allocation (e.g. 4GB, 5GB etc) from IOMMU heap, 70% of
the total time is consumed in cache cleaning. CUDA team confirmed that,
it is not always necessary to clean the CPU cache during allocation
flow. Hence provide an option to users of libnvrm_mem to skip cache
cleaning whenever required.

Bug 4628529

Change-Id: I9f4cdc930fcc673b69344f0167c8bc1378ec8d61
Signed-off-by: Ketan Patil <ketanp@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3192376
Reviewed-by: Sachin Nikam <snikam@nvidia.com>
Reviewed-by: Pritesh Raithatha <praithatha@nvidia.com>
GVS: buildbot_gerritrpt <buildbot_gerritrpt@nvidia.com>

include/linux/nvmap.h

@@ -43,6 +43,7 @@
 #define NVMAP_HANDLE_CACHE_SYNC      (0x1ul << 7)
 #define NVMAP_HANDLE_CACHE_SYNC_AT_RESERVE      (0x1ul << 8)
 #define NVMAP_HANDLE_RO	             (0x1ul << 9)
+#define NVMAP_HANDLE_SKIP_CACHE_CLEAN (0x1ul << 10)
 
 #ifdef NVMAP_CONFIG_PAGE_POOLS
 ulong nvmap_page_pool_get_unused_pages(void);