regulator: add new PMIC PF0900 support

Add binding document and driver.

Signed-off-by: Joy Zou <joy.zou@nxp.com>
---
Changes in v3:

binding part
- change regulator node names into lowercase.
- add more description for nxp,i2c-crc-enable.
- remove the unnecessary nxp,dvs-run/standby-voltage property.
  These changes come from review comments:
  https://lore.kernel.org/imx/e9f38e38-7df7-4d19-b5c0-2f18a...
- add regulator-state-mem property for example.

driver part
- convert to use maple tree register cache.
- change of_match_ptr() name to lowercase since dt-binding changed.
- add more nxp,i2c-crc-enable description for commit message.
- remove the of_parse_cb and dvs from pf0900_regulators since the
  unnecessary property nxp,dvs-run/standby-voltage removed.
- add set_suspend_enable/disable/voltage for the SW regulator_ops.
  the run/standby voltage can be adjusted via the API which regulator
  driver provides is recommended.
  These changes come from binding review comments:
  https://lore.kernel.org/imx/e9f38e38-7df7-4d19-b5c0-2f18a...
- add bitfield.h header due to build issue.
- correct the sw4 id.
- add PF0900 prefix for short macro define in order to avoid duplication.
- merge the same mask define in order to simplify code.
- Link to v2: https://lore.kernel.org/r/20250721-b4-pf09-v2-v2-0-e2c568...

Changes in v2:

binding part
- modify the binding file name to match compatible string.
- add one space for dt_binding_check warning.
- remove unnecessary quotes from "VAON".
- remove the unnecessary empty line.
- move unevaluatedProperties after the $ref.
- move additionalProperties after regulator type.
- remove unnecessary regulator description

driver part
- modify the copyright comment block to C++ style.
- add reg_read/write for regmap_bus.
- remove original pf0900_pmic_read/write.
- remove many regulator operations.
- use regmap_read replace pf0900_pmic_read.
- use regmap_update_bits and regmap_write_bits replace pf0900_pmic_write.
- move the code from pf0900.h to pf0900-regulator.c and delete the header file.
- remove unmask status interrupts and add unmask regulator interrupts.
- remove many interrupts check warning print from irq_handler.
- add notifier for regulator event.
- remove unused macro define.
- add PF0900 prefix for IRQ macro define in order to avoid duplication.
- use GENMASK() and BIT() to replace mask marco define
- remove redundant enum pf0900_chip_type.
- remove redundant print info and comments.
- add dvs property present check because this property is optional.
- remove ret == -EINVAL check from sw_set_dvs() function.
- Link to v1: https://lore.kernel.org/imx/20250617102025.3455544-1-joy....

---
Joy Zou (2):
      dt-bindings: regulator: add PF0900 regulator yaml
      regulator: pf0900: Add PMIC PF0900 support

 .../devicetree/bindings/regulator/nxp,pf0900.yaml  | 163 ++++
 drivers/regulator/Kconfig                          |   8 +
 drivers/regulator/Makefile                         |   1 +
 drivers/regulator/pf0900-regulator.c               | 975 +++++++++++++++++++++
 4 files changed, 1147 insertions(+)
---
base-commit: 84b92a499e7eca54ba1df6f6c6e01766025943f1
change-id: 20250714-b4-pf09-v2-91cdee6d1272

Best regards,
-- 
Joy Zou <joy.zou@nxp.com>