We need to know SoC type and features for cases where the same SoC
may be installed in various versions on the same board and would need
a separate dts file otherwise for the different variants.

For example, am3703 is pin compatible with omap3630, but has sgx and
iva accelerators disabled. We must not try to access the sgx or iva
module registers on am3703, and need to set the unavailable devices
disabled early.

Let's also detect omap3430 as that is needed for display subsystem
(DSS) reset later on, and GP vs EMU or HS devices. Further SoC
specific disabled device detection can be added as needed, such as
dra71x vs dra76x rtc and usb4.

Cc: Adam Ford <aford173@gmail.com>
Cc: André Hentschel <nerv@dawncrow.de>
Cc: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>