Add clock functions to initialize, enable, and disable the FCPU clock
shapers, based on the FCPU voltage rail state.  These will be used by
the DFLL clocksource driver code.

This version of the patch contains a fix for a problem noticed by Andrew
Chew <achew@nvidia.com>, where some of the FINETRIM_R bitfields were
incorrectly defined.

Based on code originally written by Aleksandr Frid <afrid@nvidia.com>.
Signed-off-by: Paul Walmsley <pwalmsley@nvidia.com>
Cc: Andrew Chew <achew@nvidia.com>
Reviewed-by: Andrew Chew <achew@nvidia.com>
Cc: Matthew Longnecker <mlongnecker@nvidia.com>
Cc: Aleksandr Frid <afrid@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>