ion: convert system heap to alloc_page()

vmalloc() allocates pages and maps them into kernel space.  If nobody
requires the area to be mapped in kernel space, this uses potentially
valuable VM address space.  Split into separate allocation and mapping
of pages.

Change-Id: I98411b93edea67c2068e20b5e48708fb38a4cd1f
Signed-off-by: David Schleef <ds@ti.com>
Signed-off-by: Tyler Luu <tluu@ti.com>

Conflicts:
	drivers/gpu/ion/ion_system_heap.c
ION : ION buffers caching support

ION buffers caching support (ION, TILER 1D buffers).

ION map is enhanced to map ion buffers as cached pages
This patch also adds IOCTLs in ION to flush and invalidate
the cached buffers
Note: TILER 2D buffers cant be mapped as cached regions to
MPU due to DMM limitation

Change-Id: I8780f5f55b7eeee0c90977af1dde66b6885cd791
Signed-off-by: Kalpesh Patil <kalpeshpatil@ti.com>
Signed-off-by: Devaraj Rangasamy <dev@ti.com>
Signed-off-by: Lajos Molnar <lajos@ti.com>
Signed-off-by: Varadarajan, Charulatha <charu@ti.com>

Conflicts:
	drivers/gpu/ion/ion_priv.h