MLK-11322-01 ARM: dts: imx: add ocram node used for lpm code

MLK-11322-01 ARM: dts: imx: add ocram node used for lpm code

Reserve iram space for low power code. The first 16KB space
is used for suspend/resume and cpuidle. Another 4KB space is
for busfreq code.

for i.MX6SX, it has a dedicated ocram space start at 0x8f8000
for low power code.

Signed-off-by: Bai Ping <b51503@freescale.com>