ARM: keystone2: rename init_meminfo to pv_fixup

The init_meminfo() method is not about initialising meminfo - it's about
fixing up the physical to virtual translation so that we use a different
physical address space, possibly above the 4GB physical address space.
Therefore, the name "init_meminfo()" is confusing.

Rename it to pv_fixup() instead.

Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Tested-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>