soc: imx: gpcv2: add support for optional resets

Normally the reset for the devices inside the power domain is
triggered automatically from the PGC in the power-up sequencing,
however on i.MX8MM this doesn't work for the GPU power domains.

Add support for triggering the reset explicitly during the power
up sequencing.

Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>