cdx: add sysfs for subsystem, class and revision

cdx: add sysfs for subsystem, class and revision

CDX controller provides subsystem vendor, subsystem device, class and
revision info of the device along with vendor and device ID in native
endian format. CDX Bus system uses this information to bind the cdx
device to the cdx device driver.

Co-developed-by: Puneet Gupta <puneet.gupta@amd.com>
Signed-off-by: Puneet Gupta <puneet.gupta@amd.com>
Co-developed-by: Nipun Gupta <nipun.gupta@amd.com>
Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com>
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Tested-by: Nikhil Agarwal <nikhil.agarwal@amd.com>
Link: https://lore.kernel.org/r/20231017160505.10640-8-abhijit.gangurde@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>