clk: add config option HAVE_CLK_PREPARE into Kconfig
clk: add config option HAVE_CLK_PREPARE into Kconfig

The commit 40d3e0f (clk: provide prepare/unprepare functions) provides
the config option HAVE_CLK_PREPARE for platforms that have
prepare/unprepare implementation to select.  This patch adds the option
into drivers/clk/Kconfig, so that it can be actually selected.

Signed-off-by: Shawn Guo <912cf7eb7d8018e2943586ae6657d21fd4e38239@linaro.org>
Cc: Russell King <f6aa0246ff943bfa8602cdf60d40c481b38ed232@arm.linux.org.uk>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas