kernel: mmu: introduce arch_page_phys_get()

This adds a new function prototype for arch_page_phys_get()
which will be used to translate mapped virtual addresses back
to physical memory addresses. This is needed for the future
k_mem_unmap() function which requires this to find
the corresponding page frame. It is faster to look through
the page tables instead of doing linear search of the page
frame array.

A weak function is provided in case arch_page_phys_get()
is not implemented at the arch level. This simply goes
through all the page frame and find the one which has
mapped to the virtual address.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>
2 files changed