Currently, this driver calls clk_prepare and clk_unprepare from
interrupt context too but these should be called from sleepable
context only. To fix this issue, this commit splits out
clk_enable/disable and clk_prepare/unprepare, and it places
clk_prepare/unprepare calls into the module probe/remove function.

Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Reviewed-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>