Per AM62x SoC datasheet[0] L2 cache is 512KB.

[0] https://www.ti.com/lit/gpn/am625 Page 1.

Fixes: f1d17330 ("arm64: dts: ti: Introduce base support for AM62x SoC")
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20230320044935.2512288-1-vigneshr@ti.comSigned-off-by: Nishanth Menon <nm@ti.com>