patch - arm - define SYS_CACHELINE_SIZE for mx5

patch - arm - define SYS_CACHELINE_SIZE for mx5

mx5 is a cortex-a8 which has 64 byte cache lines. i'll need this for
adding gadget support to usbarmory, but it's a property common the the
entire SoC family - may as well make it available to all MX5 boards

Works on usbarmory; compile-tested on mx53loco and mx51_efikamx too

Signed-off-by: Chris Kuethe <chris.kuethe@gmail.com>
Cc: Tom Rini <trini@konsulko.com>
Cc: Matthew Starr <mstarr@hedonline.com>
Cc: Andrej Rosano <andrej@inversepath.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Chris Kuethe <chris.kuethe@gmail.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Reviewed-by: Fabio Estevam <fabio.estevam@freescale.com>