spi: spi-msm-geni: Set IEOB for MHI on SPI RX only case

This change sets EOB bit as 1 in case of RX only transfer to get callback.
This way we will have CONFIG and GO TREs consumed on TX with rp updated
properly on receiving the callback on TX channel.

If EOB bit is not set, config and go TREs on TX will not have further
read pointers updated and over the time, we will run out of space
for TX channel TREs.

Change-Id: I584106ce173b1719eb0215c0c8bc879bf1e96ef1
Signed-off-by: Mukesh Kumar Savaliya <msavaliy@codeaurora.org>