usb: gadget: u_bam_data: Fix bam2bam_ipa port related check

Commit c6079f4e ("USB: f_mbim: Add support for BAM-DMUX transport")
has moved creating bam2bam_data_port for MBIM function from mbim_init()
to mbim_bind_config() which fails check of port_num against
n_bam2bam_data_ports while moving to RNDIS USB composition. Fix this
issue by avoiding check of port_num against n_bam2bam_data_ports as
u_bam_data_func_to_port() is already taking care of checking upper bound
for port number.

CRs-Fixed: 905382
Change-Id: I0d42a0f9a3592dff5db9a060b901c3f6070106e3
Signed-off-by: Mayank Rana <mrana@codeaurora.org>