cdx: Remove cdx controller list from cdx bus system

Remove xarray list of cdx controller. Instead, use platform bus
to locate the cdx controller using compat string used by cdx
controller platform driver.
Also, use ida to allocate a unique id for the controller.

Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com>
Link: https://lore.kernel.org/r/20231017160505.10640-2-abhijit.gangurde@amd.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>