arm64/sysreg: Update SMIDR_EL1 to DDI0601 2025-06

Update the definition of SMIDR_EL1 in the sysreg definition to reflect the
information in DD0601 2025-06. This includes somewhat more generic ways of
describing the sharing of SMCUs, more information on supported priorities
and provides additional resolution for describing affinity groups.

Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>