msm: ipa: Setting appropriate config on MHI ep

Couple of configuration updates on MHI ep,

 - During MHI suspend sequence,
   suspend DL channels first and followed by UL channels.
   Because, if MHI suspended during high tput scenario,
   there could be a chance that Q6 is still pumping data towards it.
   Due to which UL channels disconnection
   will fail and assert the device.

 - Set ep_delay on MHI CLIENT PROD ep upon connect,
   to prevent some random data getting into IPA
   before even Q6 configures it.

 - During SSR in pre-shutdown cleanup, set ep_delay and holb on MHI ep's
   to make sure there is no ipa stall due to some packet in/out.
   Since the ep configs are done by Q6 and which is down in SSR.

Change-Id: Ie315892a2d1403a7e1f2ecf40c7b6c12d4e93c91
Signed-off-by: Mohammed Javid <mjavid@codeaurora.org>