wigig_sensing: enable data read in non-burst sizes

Data read over SPI was guaranteed to be in a full burst size. This change
enables FW to raise the Data Ready DRI earlier, before the full burst is
ready. The driver must handle the case where data size reported by the HW
is less than a full burst, and then execute another iteration until the
whole burst is read.

This change causes a performance optimization, since the FW can raise the
Data Ready DRI earlier. The whole burst data is usually in place when the
driver handles it.

Change-Id: I98966ec5c1ef614c3c145e99bb3327febe1ebe74
Signed-off-by: Gidon Studinski <gidons@codeaurora.org>