power: replace magic numbers with macros

Replace magic numbers in buckval2votl() & buckvolt2val() with macros to
help with clarity and correlate what the numbers correspond to in the
TPS65219 datasheet.

Signed-off-by: Shree Ramamoorthy <s-ramamoorthy@ti.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
2 files changed