ENGR00174323 vpu: Fix system hang issue of multi-instances processing

ENGR00174323 vpu: Fix system hang issue of multi-instances processing

VPU registers have been mapped with ioremap() at probe which
L_PTE_XN is 1, and the same physical address must be mapped multiple
times with same type when doing mmap() to user space, so also need
to set it to 1. Otherwise, there may be unexpected result in video
codec.
Here, Use new defined pgprot_noncachedxn for vm_page_prot in mmap().

Signed-off-by: Sammy He <r62914@freescale.com>