arm64: dts: ti: k3-j7200-som: Describe OSPI flash partition info

commit cc044fba21edc9ca24fbb93a5be01ebcd6d2e087 from
git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git

Describe OSPI flash partition information in device tree
so as to remove passing partition information in `mtdparts`
commandline parameter.

Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Xulin Sun <xulin.sun@windriver.com>