staging: ccree: replace open coded loop with for

Replace open coded register writing loop with a for.
Further simplify code by using a local var to precompute
the register address for readability.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>