arm64: Update setup_arch() comment on interrupt masking

DAIF_PROCCTX_NOIRQ contains the FIQ bit. Update the comment as only
asynchronous aborts are unmasked and FIQ is still masked.

Signed-off-by: Ryo Takakura <takakura@valinux.co.jp>
Link: https://lore.kernel.org/r/20240228022836.1756-1-takakura@valinux.co.jp


Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>