soc: ti: k3-socinfo: Add entry for J721S2 SoC family

J721S2 SoC's JTAG PARTNO is 0xBB75.

Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Kishon Vijay Abraham I <kishon@ti.com>
Link: https://lore.kernel.org/r/20211203120913.14737-1-a-govindraju@ti.com