mfd: stm32-lptimer: Add support for stm32mp25

mfd: stm32-lptimer: Add support for stm32mp25

Add support for STM32MP25 SoC.
A new hardware configuration register (HWCFGR2) has been added, to gather
number of capture/compare channels, autonomous mode and input capture
capability. The full feature set is implemented in LPTIM1/2/3/4. LPTIM5
supports a smaller set of features. This can now be read from HWCFGR
registers.

Add new registers to the stm32-lptimer.h: CCMR1, CCR2, HWCFGR1/2 and VERR.
Update the stm32_lptimer data struct so signal the number of
capture/compare channels to the child devices.
Also Remove some unused bit masks (CMPOK_ARROK / CMPOKCF_ARROKCF).

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20250429125133.1574167-3-fabrice.gasnier@foss.st.com
Signed-off-by: Lee Jones <lee@kernel.org>