msm_bam_rmnet: Use Probe Method for Enumerating BAM

Use probe mechanism when enumerating network interfaces in the
BAM transport driver. This will ensure that the BAM network
interfaces are enumerated only on targets which has the BAM DMUX
driver and associated hardware enabled.
Remove references and functionality under CONFIG_HAS_EARLYSUSPEND.

Change-Id: Iecbd361e9db173c236f0589a5361215a23a225d6
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>