board: ti: am57xx: Add dt support for BeagleBoard-X15 revC

Add support for selecting proper dtb for
am57xx BeagleBoard X15 revC u-boot from FIT

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
4 files changed