ARM: dts: ipq8074: Add peripheral nodes

Add serial, i2c, bam, spi, qpic peripheral nodes.

While here, fix the PMU node's irq trigger to avoid
the boot warnings from GIC.

Reviewed-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>