mei: add trc detection register to sysfs

The glitch detection HW (TRC) save it status information into
TRC status register.
Make it available to user-space via read-only sysfs file.
The TRC register is availab for PCH15 gen and newer, for older
platforms reading the sysfs file will fail with EOPNOTSUPP.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20191107104445.19101-1-tomas.winkler@intel.com


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