Revert "arch: xtensa: Use reset-vector.S in booloader code"
Revert "arch: xtensa: Use reset-vector.S in booloader code"

This reverts commit 9987c2e2f99b279a9949ac2419f24f6162ac2e0a
which spills SoC configs into architecture files and is not
exactly desirable. So revert it.

Signed-off-by: Daniel Leung <d94e04d205b5962d7873a139ef298b03c1717f72@intel.com>

nashif/zephyr,Vudentz/zephyr,Vudentz/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,Vudentz/zephyr,galak/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,nashif/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,nashif/zephyr,Vudentz/zephyr,Vudentz/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,Vudentz/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr