clk:mmp:clk-of-mmp2: Free memory and Unmap region obtained by kzalloc and of_iomap

Free memory and memory mapping , if mmp2_clk_init is not successful.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
[sboyd@codeaurora.org: Put return at the right place]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>