msm: ipa: gsi: mhi: Configure appropriate polling mode bit for MHI ep

For MHI --> IPA pipe:
When resuming due to transition to M0,
set the polling mode bit to 0. In other cases,
restore it's value form when you stopped the channel.

For IPA-->MHI pipe:
Always restore the polling mode bit.

Change-Id: Ic856eb1c0dea35eb852bcc831ca29baba7f70860
Signed-off-by: Mohammed Javid <mjavid@codeaurora.org>