Make the hyp vector table entries local functions so they
are not accidentally referred to outside of this file.

Using SYM_CODE_START_LOCAL matches the other vector tables (in hyp-stub.S,
hibernate-asm.S and entry.S)
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210222164956.43514-1-joey.gouly@arm.comSigned-off-by: Will Deacon <will@kernel.org>