Add CS35L41 shared boost feature

Add CS35L41 shared boost feature

Merge series from Lucas Tanure <lucas.tanure@collabora.com>:

Valve's Steam Deck uses CS35L41 in shared boost mode, where both speakers
share the boost circuit.
Add this support in the shared lib, but for now, shared boost is not
supported in HDA systems as would require BIOS changes.

Based on David Rhodes shared boost patches.

Also, fix boost config overwriting in IRQ found in the review and do a
small refactor of the code.