disp: msm: drmP.h removed, add new headers

Commit ("drm: delete drmP.h + drm_os_linux.h") removes the
drmP header file. This changes updates the msm driver
by adding the individually required header files.

Change-Id: I360aa028c2ce75317d33da988b36164041177014
Signed-off-by: Samantha Tran <samtran@codeaurora.org>
Signed-off-by: Nilaan Gunabalachandran <ngunabal@codeaurora.org>

msm/msm_mmu.h

@@ -19,6 +19,7 @@
 #define __MSM_MMU_H__
 
 #include <linux/iommu.h>
+#include <linux/dma-mapping.h>
 
 struct msm_mmu;