linux-phytec-fsl

MLK-14439-3 arm: imx: support amp soc pm on 4.9

- let the arch/arm/mach-imx/mu.c do the
AMP PM only, add the IRQF_SHARED to its isr.
- remove the rpmsg implementations in this
mu driver.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>