arm64: vdso: Use GFP_KERNEL for allocating compat vdso and signal pages

There's no need to allocate the compat vDSO and signal pages using
GFP_ATOMIC allocations, so use GFP_KERNEL instead.

Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/20210318170738.7756-2-will@kernel.org


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>