[ARM] 4568/1: fix l2x0 cache invalidate handling of unaligned addresses

The l2x0_inv_range() function doesn't handle unaligned addresses
correctly. It's necessary to clean the cache lines that are at the
start and end of the invalidate range, if the addresses are not aligned,
to prevent corruption of other data sharing the same cache line.

Signed-off-by: Rui Sousa <rui.p.m.sousa@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>