arm64: Drop unnecessary include from asm/smp.h

asm/pointer_auth.h is not needed anymore in asm/smp.h, as 62a679cb
("arm64: simplify ptrauth initialization") removed the keys from the
secondary_data structure.

This also cures a compilation issue introduced by f227e3ec
("random32: update the net random state on interrupt and activity").

Fixes: 62a679cb ("arm64: simplify ptrauth initialization")
Fixes: f227e3ec ("random32: update the net random state on interrupt and activity")
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>