msm: smd: add adsp restart notifier callback

Starting with 8974, the proper name to register the SMD_Q6 subsystem
restart notifier callback changed from "lpass" to "adsp".  Register an
additional callback notifier under the "adsp" name to support both
legacy targets and 8974.  Only one SMD_q6 callback will ever be called on
a target.

CRs-Fixed: 404860
Change-Id: I57928b6e9f24e356db8971100be06ca3158b1f14
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>