octeontx2-af: debugfs: Add Channel info to RPM map

Display channel info in the RPM map debugfs output.

With this, cat /sys/kernel/debug/cn10k/rvu_pf_rpm_map
would display channel number for each device in addition to
the existing data.

Sample output:
PCI dev         RVU PF Func     NIX block       rpm     LMAC    CHAN
0002:02:00.0    0x400           NIX0            rpm0    LMAC0   256

Signed-off-by: Linu Cherian <lcherian@marvell.com>
Link: https://patch.msgid.link/20240912161450.164402-3-lcherian@marvell.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>