platform/x86/amd/pmf: Add debugfs information

Add debugfs support to the PMF driver so that using this interface the
live counters from the PMFW can be queried to see if the power parameters
are getting set properly when a certain power mode change happens.

Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://lore.kernel.org/r/20220802151149.2123699-5-Shyam-sundar.S-k@amd.com


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