USB: gadget: u_bam: Check IPA resource only for BAM2BAM_IPA mode

Commit I8261e53de774099062972fbdd496d42cba8140f8:"usb: gadget:
prevent sending packets to IPA when in suspend" has added  a check
for not giving data packets to IPA till IPA is not ready. Due to this
check, USB driver is not at all giving data packets to modem and results
in data call failure in System to BAM mode.  Hence, restrict this check
only for BAM2BAM_IPA transport mode.

CRs-Fixed: 638790
Change-Id: I119f6e415e1f7fb322cb34c89d5f76b11065ea14
Signed-off-by: Sujeet Kumar <ksujeet@codeaurora.org>