arch: suspend CONFIG_SOC's doomsday
arch: suspend CONFIG_SOC's doomsday

This option is useful to have for a flatter hierarchy for one-off SoCs
that aren't split into family and series from the silicon vendor
perspective.

The commit saying it was going to go away is from 2 years ago; it
hasn't happened and it doesn't seem to need to happen. Just delete it.

Signed-off-by: Marti Bolivar <fd5da480b758a78208111e6ae5c6806e1f887137@foundries.io>

explora26/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,nashif/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,Vudentz/zephyr,Vudentz/zephyr,punitvara/zephyr,punitvara/zephyr,ldts/zephyr,galak/zephyr,ldts/zephyr,Vudentz/zephyr,galak/zephyr,explora26/zephyr,Vudentz/zephyr,nashif/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,Vudentz/zephyr,ldts/zephyr,punitvara/zephyr,punitvara/zephyr,explora26/zephyr,nashif/zephyr,galak/zephyr,finikorg/zephyr,explora26/zephyr,punitvara/zephyr,explora26/zephyr,GiulianoFranchetto/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr