spi_qsd: Update device tree entries and binding doc

Update device tree entries to comply with latest practice.
Change proprietary entry name from "infinite_mode" to
"qcom,infinite-mode" and specify bus-number by alias instead
of "cell-index". The following changes are updated to spi's
device-tree binding document.

CRs-Fixed: 451911
Change-Id: Id54d494c23578315b04e7682fe3a815c7db1b421
Signed-off-by: Gilad Avidov <gavidov@codeaurora.org>
4 files changed