arm64: dts: ti: k3-am62p: Add SRAM node for MCU-R5 and set wakeup source

commit 643f2b274b74b8ea55f0cc825b3f505b2603dfd2 from
git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git



AM62P devices have a 512KB sram in MCU domain. This memory can be used
by the MCU domain R5F for code and data sections.

In addition, MCU R5 can also be a wakeup source with any MCU peripheral
waking the device.

Signed-off-by: Hari Nagalla <hnagalla@ti.com>
Signed-off-by: Xulin Sun <xulin.sun@windriver.com>