arm64/mm: Update non-range tlb invalidation routines for FEAT_LPA2

FEAT_LPA2 impacts tlb invalidation in 2 ways; Firstly, the TTL field in
the non-range tlbi instructions can now validly take a 0 value for the
4KB granule (this is due to the extra level of translation). Secondly,
the BADDR field in the range tlbi instructions must be aligned to 64KB
when LPA2 is in use (TCR.DS=1). Changes are required for tlbi to
continue to operate correctly when LPA2 is in use.

KVM only uses the non-range (__tlbi_level()) routines. Therefore we only
solve the first problem with this patch.

It is solved by always adding the level hint if the level is between [0,
3] (previously anything other than 0 was hinted, which breaks in the new
level -1 case from kvm). When running on non-LPA2 HW, 0 is still safe to
hint as the HW will fall back to non-hinted. While we are at it, we
replace the notion of 0 being the non-hinted seninel with a macro,
TLBI_TTL_UNKNOWN. This means callers won't need updating if/when
translation depth increases in future.

Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>