octeontx2-af: add debugfs entries for CPT block

Add entries to debugfs at /sys/kernel/debug/octeontx2/cpt.

cpt_pc: dump cpt performance HW registers.
Usage:
cat /sys/kernel/debug/octeontx2/cpt/cpt_pc

cpt_ae_sts: show cpt asymmetric engines current state
Usage:
cat /sys/kernel/debug/octeontx2/cpt/cpt_ae_sts

cpt_se_sts: show cpt symmetric engines current state
Usage:
cat /sys/kernel/debug/octeontx2/cpt/cpt_se_sts

cpt_engines_info: dump cpt engine control registers.
Usage:
cat /sys/kernel/debug/octeontx2/cpt/cpt_engines_info

cpt_lfs_info: dump cpt lfs control registers.
Usage:
cat /sys/kernel/debug/octeontx2/cpt/cpt_lfs_info

cpt_err_info: dump cpt error registers.
Usage:
cat /sys/kernel/debug/octeontx2/cpt/cpt_err_info

Signed-off-by: Suheil Chandran <schandran@marvell.com>
Signed-off-by: Srujana Challa <schalla@marvell.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>