gpu: ion: Request highmem pages for IOMMU heap
gpu: ion: Request highmem pages for IOMMU heap

When allocating pages for IOMMU heap it is advantageous
to try to allocate pages from highmem in addition to
lowmem since clients using the IOMMU heap can use
either highmem or lowmem.

CRs-fixed: 430457
Change-Id: Ifc794fc344c67dd53d8f7cebf86536ab9d44ed6c
Signed-off-by: Olav Haugan <fbf4ddd114d5f0aa83cb721b7dacab8a264ccf22@codeaurora.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas