ASoC: cs35l56: Switch to using the IRQ from the SoundWire core

Richard Fitzgerald <rf@opensource.cirrus.com> says:

At the time the cs35l56 driver was written the only way to get interrupts
from the SoundWire core was to implement a custom handler inside the
interrupt_callback() function.

The SoundWire core now provides a virtual IRQ for notifying ImpDef
interrupts, and switching to this simplifies the code and also makes it
more similar to the normal interrupt handling of I2C/SPI (though some
SoundWire specials are still needed).

Patches #1 and #2 do some preparatory code shuffling so that there is
less clutter in patch #4.

Patch #3 changes the SoundWire core code to create the virtual ImpDef IRQ
before calling the codec drive probe() so that the IRQ can be requested in
probe().

Link: https://patch.msgid.link/20260810104045.60701-1-rf@opensource.cirrus.com

diff --cc sound/soc/codecs/Kconfig
Simple merge