Z_ISR_DECLARE: ensure proper alignment on 64-bit targets
Z_ISR_DECLARE: ensure proper alignment on 64-bit targets

Prevent spurious unexpected alignment on 64-bit targets.

Signed-off-by: Nicolas Pitre <76342682d5afc62854e1102d9578521fe1ed6813@baylibre.com>

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