USB: gadget: u_bam_data: Allow connect work to run once during resume

In some scenarios like suspend/resume, connect work is scheduled two
times during resume. This could cause setting ipa handlers to invalid
values and results in disconnect ipa failures. Due to this, subsequent
connect ipa always returns in success with pipes already connected
message and causes ip address not assigning. Hence add proper checks
in connect work so that not to allow connect work to run for a second
time.

CRs-Fixed: 848456
Change-Id: I7cf65878b542ef86c0b00daae9255dc7902a99f9
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>
Signed-off-by: Tarun Gupta <tarung@codeaurora.org>