msm: mdm: add a parameter for the name used to register for SSR

The name that that mdm driver uses to register with SSR is used
by other drivers to register for notifications, so it must be a
system-wide, known string. The mdm driver was previously generating
an arbitrary string that only it knew about. The name needs to be
passed to the mdm driver instead of it being auto-generated.

Change-Id: If8dab185b5599e95f2087bab97d48e5c72311279
Signed-off-by: Joel King <joelking@codeaurora.org>