mtd: rawnand: omap_elm: Add compatible for AM64 ELM

The AM64 SoC has the Error Locator Module. Add compatible id for it.

Signed-off-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220326080726.30372-4-rogerq@kernel.org