bus: mhi: core: Move to an error state on any firmware load failure

Move MHI to a firmware download error state for a failure to find
the firmware files or to load SBL or EBL image using BHI/BHIe. This
helps detect an error state sooner and shortens the wait for a
synchronous power up timeout.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>