arm64: dts: ti: k3-j7200: Correct the d-cache-sets info

A72 Cluster (chapter 1.3.1 [1]) has 48KB Icache, 32KB Dcache and 1MB L2 Cache
 - ICache is 3-way set-associative
 - Dcache is 2-way set-associative
 - Line size are 64bytes

32KB (Dcache)/64 (fixed line length of 64 bytes) = 512 ways
512 ways / 2 (Dcache is 2-way per set) = 256 sets.

So, correct the d-cache-sets info.

[1] https://www.ti.com/lit/pdf/spruiu1



Fixes: d361ed88 ("arm64: dts: ti: Add support for J7200 SoC")
Reported-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20211113042640.30955-1-nm@ti.com