rpmsg: glink: spi: increment channel ref count before intent request

Releasing the glink spi channel while a client is waiting on
intent request queue can result in use after free case.

To avoid channel release in this case, first incrementing
channel ref count and then waiting for intent response.

In ssr case  waking up threads waiting for intent to decrement
the channel ref count, so that channel release operation is not delayed.

CR-Fixed: 2400497
Change-Id: I109db54e0203d47ba897a95d426082dab5d1bc23
Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>