tests: Kconfig: Added a new kconfig.
tests: Kconfig: Added a new kconfig.

A new Kconfig to help test the userspace mode. Needed for devices
which have userspace capabilities but are not enabled by default.
This kconfig enables the userspace for the devices which have
CONFIG_ARCH_HAS_USERSPACE enabled.

Signed-off-by: Adithya Baglody <06b44f6fa9a97a2b955c2d2cd070279967447860@intel.com>

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