clk: sunxi: drop an unnecesary kmalloc

clk_register will copy this information, so we can just use a normal
array and do one less dynamic allocation.

Signed-off-by: Emilio López <emilio@elopez.com.ar>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>