arch: arm64: correct vector_table alignment
arch: arm64: correct vector_table alignment

The 2K alignment assembler directives should be under
'SECTION_SUBSEC_FUNC(exc_vector_table,_vector_table_section,_vector_table)'
Otherwise the _vector_table is actually 0x80 bytes aligned.

Signed-off-by: Peng Fan <d3c162a96b7fb54e5d94bc77bc2c7cbbce10806f@nxp.com>

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