mfd: intel_soc_pmic_core: ADD PWM lookup table for CRC PMIC based PWM

On some BYT PLatform the PWM is controlled using CRC PMIC. Add a lookup
entry for the same to be used by the consumer (Intel GFX)

CC: Samuel Ortiz <sameo@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>