ARM: dts: AM33XX: Add ELM node

ELM hardware engine is used for locating bit-flips in NAND data
This patch is required for working of hardware based NAND ECC schemes
with DT support.

Signed-off-by: Philip Avinash <avinashphilip@ti.com>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Pekon Gupta <pekon@ti.com>
Signed-off-by: Benoit Cousson <benoit.cousson@linaro.org>