regulator: tps65090: rename driver name and regulator name

To make the names proper and more appropriate:
Rename the driver name from tps65090-regulator to tps65090-pmic.
Rename the regulators from TPS65090_ID_* to TPS65090_REGULATOR_*

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>