platform/x86/amd/pmf: Move out of BIOS SMN pair for driver probe

The current SMN index used for the driver probe seems to be meant
for the BIOS pair and there are potential concurrency problems that can
occur with an inopportune SMI.

It is been advised to use SMN_INDEX_0 instead of SMN_INDEX_2, which is
what amd_nb.c provides and this function has protections to ensure that
only one caller can use it at a time.

Fixes: da5ce22d ("platform/x86/amd/pmf: Add support for PMF core layer")
Co-developed-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
Signed-off-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://lore.kernel.org/r/20230406164807.50969-4-Shyam-sundar.S-k@amd.com


Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>