ARM: dts: omap4-panda-a4: Add missing model and compatible properties

ARM: dts: omap4-panda-a4: Add missing model and compatible properties

When moving the model and compatible properties out of the common
Pandaboard files and in to the specific boards, the omap4-panda-a4
file wasn't updated as well and so has lacked a model and compatible
entry ever since.

Fixes: a1a57abaaf82 ("ARM: dts: omap4-panda: Fix model and SoC family details")
Signed-off-by: Tom Rini <trini@konsulko.com>
Link: https://lore.kernel.org/r/20250123174901.1182176-2-trini@konsulko.com
Signed-off-by: Kevin Hilman <khilman@baylibre.com>