x86: gen_mmu: unify size display in hex

This unifies all the display of region size in hex.
Some of them are there to aid in figuring out the end of
a memory region so it is easier if they are already in hex.

This also fixes the display of address range where the end
is off by one and should be (base + size - 1).

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