ARM: DTS: AM33XX: Add nodes for OCMC RAM and WKUP-M3

Since AM33XX supports only DT-boot, this is needed
for the appropriate device nodes to be created.

Note: OCMC RAM is part of the PER power domain and supports
retention. The assembly code for low power entry/exit will
run from OCMC RAM. To ensure that the OMAP PM code does not
attempt to disable the clock to OCMC RAM as part of the
suspend process add the no_idle_on_suspend flag.

Signed-off-by: Vaibhav Bedia <vaibhav.bedia@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Paul Walmsley <paul@pwsan.com>