mfd: intel_soc_pmic_bxtwc: Use IRQ domain for PMIC devices

While design wise the idea of converting the driver to use
the hierarchy of the IRQ chips is correct, the implementation
has (inherited) flaws. This was unveiled when platform_get_irq()
had started WARN() on IRQ 0 that is supposed to be a Linux
IRQ number (also known as vIRQ).

Rework the driver to respect IRQ domain when creating each MFD
device separately, as the domain is not the same for all of them.

Fixes: 57129044 ("mfd: intel_soc_pmic_bxtwc: Use chained IRQs for second level IRQ chips")
Tested-by: Zhang Ning <zhangn1985@outlook.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20241005193029.1929139-4-andriy.shevchenko@linux.intel.com


Signed-off-by: Lee Jones <lee@kernel.org>