kernel: init: print boot banner before static threads
kernel: init: print boot banner before static threads

The boot banner is being printed after static threads have started, for
example this is visible with tests using ztest.
This puts the banner message before starting any threads.

Signed-off-by: Anas Nashif <0d9952ec84ac43c159f6b7e7ed99a9080c00dd6e@intel.com>

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