board: ti: am57xx: Add support for detection of X15 revb1

BeagleBoard-X15 Rev B1 with SR1.1 platform have incompatible changes for HDMI
GPIO requiring new dtb support. This implies we have to properly identify
the platform now as well. Hence provide a different board name for the
Rev B1 variants.

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