mhi: core: always try forcing device into rddm when bus master requests

Let bus master determine the link states. Whenever bus master request
device to enter rddm always try enter rddm regardless of current
software state.

CRs-Fixed: 2373857
Change-Id: I9e5a993f3e7311c4367b7fd82385d4f0dcacc932
Signed-off-by: Sujeev Dias <sdias@codeaurora.org>