iw_cxgb4: add INFINIBAND_ADDR_TRANS dependency

The newly added fill_res_ep_entry function fails to link if
CONFIG_INFINIBAND_ADDR_TRANS is not set:

drivers/infiniband/hw/cxgb4/restrack.o: In function `fill_res_ep_entry':
restrack.c:(.text+0x3cc): undefined reference to `rdma_res_to_id'
restrack.c:(.text+0x3d0): undefined reference to `rdma_iw_cm_id'

This adds a Kconfig dependency for the driver.

Fixes: 116aeb88 ("iw_cxgb4: provide detailed provider-specific CM_ID information")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Thelen <gthelen@google.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>