Failure to register SGI for firmware event notification is non-fatal error
when feature is not supported by other modules such as Xen and TF-A. Add
_info level log message for such special case.

Also add XST_PM_INVALID_VERSION error code and map it to -EOPNOSUPP Linux
kernel error code. If feature is not supported or EEMI API version is
mismatch, firmware can return XST_PM_INVALID_VERSION = 4 or
XST_PM_NO_FEATURE = 19 error code.
Co-developed-by: Tanmay Shah <tanmay.shah@amd.com>
Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
Signed-off-by: Jay Buddhabhatti <jay.buddhabhatti@amd.com>
Link: https://lore.kernel.org/r/20231129112713.22718-5-jay.buddhabhatti@amd.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>