ARM: l2x0: Fix coding-style in the cache-l2x0.h

Replace tab with space after #define to be consisten with other
define in the file. Also move the bit mask below the register offsets.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>