clk: Separate OF clock code from COMMON_CLK

Clock providers may wish to use the device tree
functionality of the clock framework without using
the COMMON_CLOCK framework. Unconditionally compile
drivers/clk/clk.c and #ifdef out the COMMON_CLK
related code.

Change-Id: I0ba03bbd57879ae17bedcb8c436e031834626673
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>
(cherry picked from commit 70275397a2592031611ae1af711dc5cea65cd2ae)
[joshc: Dropped mach-msm changes, extend seperation to
drivers/clk/clk.h]
Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
[abhimany: Minor merge conflict resolution]
Signed-off-by: Abhimanyu Kapur <abhimany@codeaurora.org>