davinci: explain CLOCK_TICK_RATE of 27MHz in include/mach/timex.h
davinci: explain CLOCK_TICK_RATE of 27MHz in include/mach/timex.h

Leave a comment explaining the constant value of 27Mhz used
in include/mach/timex.h for all DaVinci platforms. Many of
the platforms actually run at 24MHz timer frequency (Eg.
EVMs of DM355, DM365 and OMAP-L1).

The comment also serves as a porting alert.

Signed-off-by: Sekhar Nori <946cfb81282bb55c59f600e7ee3d3b2c6973f7a3@ti.com>
Signed-off-by: Kevin Hilman <f9849b02abe18c1ece6bd40346458ed53f49d31b@deeprootsystems.com>

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