disp: msm: dsi: Do not call devm_clk_put() with invalid clk

Do not call devm_clk_put() if devm_clk_get() was failed for
a given clk. The devm_clk_put() does not check for the validity
of the input clk argumnet, and can cause NULL pointer dereference
or some other errors if called with invalid clk argument.

Change-Id: Ie626a5afed52a146ebd1a2092c7d9db9226dbfe0
Signed-off-by: Rajeev Nandan <rajeevny@codeaurora.org>