Trivial fix.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

This macro is used to allocate cache line size aligned stack
buffers for use with DMA hardware.

Signed-off-by: Anton Staaf <robotboy@chromium.org>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Aneesh V <aneesh@ti.com>
Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Cc: Wolfgang Denk <wd@denx.de>

c2dd0d45 added dcache_enable()
to board_init_r(). This enables d-cache for all ARM boards.
As a result some of the arm boards that are not cache-ready
are broken. Revert this change and allow platform code to
take the decision on d-cache enabling.

Also add some documentation for cache usage in ARM.

Signed-off-by: Aneesh V <aneesh@ti.com>