arm64/fpsimd: Allow CONFIG_ARM64_SME to be selected

Now that the known issues with SME have been addressed, allow SME to be
selected.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Daniel Kiss <daniel.kiss@arm.com>
Cc: David Spickett <david.spickett@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Luis Machado <luis.machado@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Richard Sandiford <richard.sandiford@arm.com>
Cc: Sander De Smalen <sander.desmalen@arm.com>
Cc: Tamas Petz <tamas.petz@arm.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yury Khrustalev <yury.khrustalev@arm.com>
Tested-By: Luis Machado <luis.machado@arm.com>
Link: https://lore.kernel.org/r/20250508132644.1395904-21-mark.rutland@arm.com


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