arm: davinci: use for_each_set_bit_from

Use for_each_set_bit_from to iterate over all the set bit in a memory
region.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Christian Riesch <christian.riesch@omicron.at>
Cc: Kevin Hilman <khilman@ti.com>
Cc: davinci-linux-open-source@linux.davincidsp.com
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Sekhar Nori <nsekhar@ti.com>