tests: protection: don't do exec tests on x86
tests: protection: don't do exec tests on x86

The IA32 MMU has no concept of a "no execute" flag, this is
unfortunately only implemented in x86_64.

Signed-off-by: Andrew Boie <aab045b28152628be6af0e556050d0381fd0a34d@intel.com>

ldts/zephyr,runchip/zephyr-cc3220,fbsder/zephyr,zephyriot/zephyr,galak/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,kraj/zephyr,punitvara/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,holtmann/zephyr,mbolivar/zephyr,rsalveti/zephyr,mbolivar/zephyr,explora26/zephyr,kraj/zephyr,fbsder/zephyr,zephyriot/zephyr,explora26/zephyr,zephyriot/zephyr,rsalveti/zephyr,Vudentz/zephyr,aceofall/zephyr-iotos,holtmann/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,fbsder/zephyr,mbolivar/zephyr,nashif/zephyr,holtmann/zephyr,explora26/zephyr,galak/zephyr,kraj/zephyr,punitvara/zephyr,rsalveti/zephyr,runchip/zephyr-cc3220,Vudentz/zephyr,ldts/zephyr,Vudentz/zephyr,Vudentz/zephyr,runchip/zephyr-cc3220,rsalveti/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,punitvara/zephyr,runchip/zephyr-cc3220,fbsder/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,rsalveti/zephyr,zephyriot/zephyr,nashif/zephyr,holtmann/zephyr,explora26/zephyr,GiulianoFranchetto/zephyr,kraj/zephyr,punitvara/zephyr,mbolivar/zephyr,ldts/zephyr,aceofall/zephyr-iotos,finikorg/zephyr,nashif/zephyr,aceofall/zephyr-iotos,finikorg/zephyr,nashif/zephyr,fbsder/zephyr,aceofall/zephyr-iotos,holtmann/zephyr,explora26/zephyr,aceofall/zephyr-iotos,mbolivar/zephyr,finikorg/zephyr,runchip/zephyr-cc3220,GiulianoFranchetto/zephyr,galak/zephyr,zephyriot/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,kraj/zephyr