clk: sprd: add missing kfree

clk: sprd: add missing kfree

[ Upstream commit 5e75ea9c67433a065b0e8595ad3c91c7c0ca0d2d ]

The number of config registers for different pll clocks probably are not
same, so we have to use malloc, and should free the memory before return.

Fixes: 3e37b005580b ("clk: sprd: add adjustable pll support")
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Signed-off-by: Chunyan Zhang <zhang.lyra@gmail.com>
Link: https://lkml.kernel.org/r/20190905103009.27166-1-zhang.lyra@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>