ARM: 8236/1: mm: fix discard_old_kernel_data

ARM: 8236/1: mm: fix discard_old_kernel_data

L1_CACHE_BYTES could be larger value than real L1 cache line size.
In that case, discard_old_kernel_data() would omit to invalidate
last bytes as much as L1_CACHE_BYTES - real cache line size.

So fix end address to "to + PAGE_SIZE -1". The bottom bits
of the address is LINELEN. that is ignored by mcrr.

Signed-off-by: Jungseung Lee <js07.lee@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>