soundwire: Move device init functionality from master

Move from master probe to the slave probe, the
device init functionality of swr slave. Provide
device remove functionality to remove a given
device from the master's list.

CRs-fixed: 2050710
Change-Id: Iee95c146d8b148e15dca5a8c10de65368cf3b55a
Signed-off-by: Karthikeyan Mani <kmani@codeaurora.org>