RDMA/hfi1: Constify 'struct bin_attribute'

The sysfs core now allows instances of 'struct bin_attribute' to be
moved into read-only memory. Make use of that to protect them against
accidental or malicious modifications.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20250114-sysfs-const-bin_attr-infiniband-v1-1-397aaa94d453@weissschuh.net


Signed-off-by: Leon Romanovsky <leon@kernel.org>