arm64: insn: Add tests for aarch64_insn_gen_logical_immediate()

Aarch64 has instructions to generate reasonably complicated 32 or 64
bit masks from only 13 bits of information.
aarch64_insn_gen_logical_immediate() has to created the immediate
encoding by spotting the patterns in the 32 or 64 bit immediate.

Despite attempts to validate or model this code, or use it as-is outside
the kernel tree, bugs still exist.

Add a self test module that tests this code in place against a golden
set of values.

Signed-off-by: James Morse <james.morse@arm.com>