arch: arm: aarch64: linker.ld: move vector table to text segment

Following changes are done:
- The vector table should be placed in text segment.
- Removed Vector relay table related entries as it is
  only applicable to aarch32.
- irq_vector_table contains ISR pointers - should be placed
  in rodata segment.
- put openocd_dbg in rodata and skip adding <linker_relocate.ld>
  as CONFIG_CODE_DATA_RELOCATION is not defined for aarch64
  currently (add later if needed).

Fixes: #22673
Signed-off-by: Abhishek Shah <abhishek.shah@broadcom.com>