bus: mhi: ep: Power up/down MHI stack during MHI RESET

bus: mhi: ep: Power up/down MHI stack during MHI RESET

[ Upstream commit 62846c3729ca3729c3668315d5349516e8c4a777 ]

During graceful shutdown scenario, host will issue MHI RESET to the
endpoint device before initiating shutdown. In that case, it makes sense
to completely power down the MHI stack as sooner or later the access to
MMIO registers will be prohibited. Also, the stack needs to be powered
up in the case of SYS_ERR to recover the device.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Link: https://lore.kernel.org/r/20221228161704.255268-2-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Stable-dep-of: 7b96306c0515 ("bus: mhi: ep: Change state_lock to mutex")
Signed-off-by: Sasha Levin <sashal@kernel.org>