arm64: dts: ti: k3-am68-sk-som: Add support for OSPI flash

AM68 SK has an OSPI NOR flash on its SOM connected to OSPI0 instance.
Enable support for the same. Also, describe the OSPI flash partition
information through the device tree, according to the offsets in the
bootloader.

Signed-off-by: Sinthu Raja <sinthu.raja@ti.com>
Signed-off-by: Udit Kumar <u-kumar1@ti.com>
Link: https://lore.kernel.org/r/20240622161835.3610348-1-u-kumar1@ti.com


Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>