power: regulator: ADD PMIC PF9453 support

power: regulator: ADD PMIC PF9453 support

Add regulator support for NXP PMIC pf9453 for imx91 qsb.

Reviewed-by: Ye Li <ye.li@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Joy Zou <joy.zou@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Rebased [1] on main and LDO SNVS access / checkpatch fixed. See also [2]
[1] https://patchwork.ozlabs.org/project/uboot/patch/20240930035531.27079-4-peng.fan@oss.nxp.com/
[2] https://lists.u-boot-project.org/pipermail/u-boot/2026-July/625613.html
Signed-off-by: Krzysztof Drobiński <krzysztof@kd-solutions.pl>