net: mana: Expose hardware diagnostic info via debugfs

net: mana: Expose hardware diagnostic info via debugfs

Add debugfs entries to expose hardware configuration and diagnostic
information that aids in debugging driver initialization and runtime
operations without adding noise to dmesg.

The debugfs directory for each PCI device is named using pci_name()
(the unique BDF address), and its creation and removal is integrated
into mana_gd_setup() and mana_gd_cleanup_device() respectively, so
that all callers (probe, remove, suspend, resume, shutdown) share a
single code path.

Device-level entries (under /sys/kernel/debug/mana/<BDF>/):
  - num_msix_usable, max_num_queues: Max resources from hardware
  - gdma_protocol_ver, pf_cap_flags1: VF version negotiation results
  - num_vports, bm_hostmode: Device configuration

Per-vPort entries (under /sys/kernel/debug/mana/<BDF>/vportN/):
  - port_handle: Hardware vPort handle
  - max_sq, max_rq: Max queues from vPort config
  - indir_table_sz: Indirection table size
  - steer_rx, steer_rss, steer_update_tab, steer_cqe_coalescing:
    Last applied steering configuration parameters

Signed-off-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260519064621.772154-1-ernis@linux.microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>