soc: Add information to identify the J742S2 SoC family

J742S2 has the same part number as J784S4 but JTAG_DEVICE_ID has a
PKG bit that tells about J742S2.

Add support for reading JTAG_DEVICE_ID and set family as J742S2 based
on that.

Link: https://www.ti.com/lit/pdf/spruje3 (TRM)
Signed-off-by: Manorit Chawdhry <m-chawdhry@ti.com>
2 files changed