drm: ARM HDLCD - get rid of devm_clk_put()

Clock is acquired with devm_clk_get() which already manages
corresponding resource.

I.e. in case of driver removal or failure on installaiton
clock resources will be automatically released and explicit
call of devm_clk_put() is not required.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Robin Murphy <robin.murphy@arm.com>

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>