u_bam_data: Add check to perform USB IPA connect and disconnect

bam_data_connect() and bam_data_disconnect() calls from atomic
context from composite driver, where as bam2bam_data_connect_work()
and bam2bam_data_disconnect_work() is scheduled from this. There
are different APIs of IPA driver called based on USB function type
which initiates IPA driver state machine. There are some cases where
before bam2bam_data_connect_work() is being executed,
bam_data_disconnect() is being called. To avoid this situation, this
change adds check which make sure that cleanup with IPA driver
happens only if it has previously been initialized.

CRs-Fixed: 718571
Change-Id: I02209686be2662c90faa6533fc0e7feb2285518a
Signed-off-by: Mayank Rana <mrana@codeaurora.org>