ARM: dts: msm: Disable BAM mode for spi dtsi node

Disable BAM mode for spi dtsi node which is used by bg.
This is done to avoid the spi-BAM transaction timeouts
that are happening only in BAM mode.

Change-Id: I3585dc6002057b9e2f1ee1477c995c3b6642d6c9
Signed-off-by: Prudhvi Yarlagadda <pyarlaga@codeaurora.org>