Rockchip RK860X regulators share the exact same functionality and
register layout as the Fairchild FAN53555 regulators.
Therefore extend the driver to add support for them.
Both types use the same vendor id in their ID1 register, so it's not
possible to distinguish them automatically.
Similarly, the types also do not match. Type 8 used by the RK8603
and RK8604 start at 500mV and increment in 6.25mv steps,
while the FAN53555 type 8 starts at 600mV and increments in 10mV steps.
And the en register is also differences.
Change-Id: Id93f85de91b79a1922b1efc27771f30dd7bc8bcb
Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
eb1731965c