net: mana: Move current_speed debugfs file to mana_init_port()

net: mana: Move current_speed debugfs file to mana_init_port()

Move the current_speed debugfs file creation from mana_probe_port() to
mana_init_port(). The file was previously created only during initial
probe, but mana_cleanup_port_context() removes the entire vPort debugfs
directory during detach/attach cycles. Since mana_init_port() recreates
the directory on re-attach, moving current_speed here ensures it survives
these cycles.

Fixes: 75cabb46935b ("net: mana: Add support for net_shaper_ops")
Signed-off-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260408081224.302308-3-ernis@linux.microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>