cnss2: add support for converged dt node

Converge dt nodes for wlan chips those share the same
PCI slot into one node. The items in this node are
split into 2 parts: common and chip specific.

The common part will be parsed during cnss probe, such as
basic power related configuration and bus type, to power
on the device and trigger pci probe;
Chip specific part will be parsed during pci probe, such as
chip specific power and feature related configurations.

With this change, cnss2 can support different chips on
one pci slot with the same image.

CRs-Fixed: 2384088
Change-Id: I08c64b6dc3cc27a479ee6fd07e3c8705cc3ac43d
Signed-off-by: Yu Wang <yyuwang@codeaurora.org>