arm64/mm: use GENMASK_ULL for TTBR_BADDR_MASK_52

The comment says this should be GENMASK_ULL(47, 12), so do that!

GENMASK_ULL() is available in assembly since:
    95b980d6 ("linux/bits.h: make BIT(), GENMASK(), and friends available in assembly")

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/all/20171221164851.edxq536yobjuagwe@armageddon.cambridge.arm.com/


Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Kristina Martsenko <kristina.martsenko@arm.com>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220708140056.10123-1-joey.gouly@arm.com


Signed-off-by: Will Deacon <will@kernel.org>