gpu: nvgpu: Remove Linux headers from mm_gk20a.h

Delte the Linux headers and make some modifications to get rid of the
minor compilation issues that resulted.

  - Add <linux/iommu.h> to os_linux.h
  - Delete #if 0 code that "flushed" a buffer in gr_gk20a.c
  - Delete FLUSH_CPU_DCACHE() macro
  - Move the cache flush definitions to <nvgpu/linux/vm.h>
    and include this header in sim_gk20a.c. This file will
    not be used by QNX so this should be fine.
  - Add <linux/pci_ids.h> to gp106/bios_gp106.c and
    gp106/mclk_gp106.c.
  - Move function to common/linux/dmabuf.h since it is a
    dmabuf related function and uses a struct device pointer
    as an argument.

JIRA NVGPU-30

Change-Id: I11f56b98524c7fac3efa91b4686592130e5f8a46
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1585510
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/common/linux/dmabuf.h

@@ -70,4 +70,7 @@ int gk20a_dmabuf_alloc_drvdata(struct dma_buf *dmabuf, struct device *dev);
 int gk20a_dmabuf_get_state(struct dma_buf *dmabuf, struct gk20a *g,
 			   u64 offset, struct gk20a_buffer_state **state);
 
+int gk20a_mm_get_buffer_info(struct device *dev, int dmabuf_fd,
+			     u64 *buffer_id, u64 *buffer_len);
+
 #endif

drivers/gpu/nvgpu/common/linux/ioctl_ctrl.c

@@ -43,6 +43,7 @@
 #include "gk20a/fence_gk20a.h"
 
 #include "os_linux.h"
+#include "dmabuf.h"
 
 #define HZ_TO_MHZ(a) ((a > 0xF414F9CD7ULL) ? 0xffff : (a >> 32) ? \
 	(u32) ((a * 0x10C8ULL) >> 32) : (u16) ((u32) a/MHZ))

drivers/gpu/nvgpu/common/linux/os_linux.h

@@ -13,10 +13,12 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+
 #ifndef NVGPU_OS_LINUX_H
 #define NVGPU_OS_LINUX_H
 
 #include <linux/cdev.h>
+#include <linux/iommu.h>
 
 #ifdef CONFIG_TEGRA_19x_GPU
 #include <nvgpu/linux/os_linux_t19x.h>