scsi: ufs: ufs-debugfs: Add error counters

People testing have a need to know how many errors might be occurring over
time. Add error counters and expose them via debugfs.

A module initcall is used to create a debugfs root directory for
ufshcd-related items. In the case that modules are built-in, then
initialization is done in link order, so move ufshcd-core to the top of the
Makefile.

Link: https://lore.kernel.org/r/20210107072538.21782-1-adrian.hunter@intel.com


Reviewed-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>