arm64: dts: msm8996: add support to blsp2_spi5

This patch adds support to blsp2_spi5 device, which is used in some of
the APQ8096 based boards.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>