UPSTREAM: regulator: rk808: remove linear range definitions with a single range

UPSTREAM: regulator: rk808: remove linear range definitions with a single range

The driver was using only linear ranges. Now we remove linear range
definitions with a single range. So we have to add an ops struct for
ranges and adjust all other ops functions accordingly.

Change-Id: I6b2dd5e035832f9460ec8a24b5214204f7a930b7
Signed-off-by: Wadim Egorov <w.egorov@phytec.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
(cherry picked from commit afcd666d9db0ebfbf2751cce1e07b548547ca82e)
Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>