regulator: tps65086: Fix 25mV ranges for BUCK regulators

The BUCK regulators 3, 4, and 5 also have a 10mV step mode,
adjust the tables and logic to reflect the data-sheet for
these regulators.

fixes: d2a2e729 ("regulator: tps65086: Add regulator driver for the TPS65086 PMIC")
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>