Audit Cross Compile Support

[AKASHI Takahiro]

Hello Clayton,

I picked up your patches and tried to cross-build the package for
AArch64. In the following code of lib/gen_tables.py,

	parser.add_argument('--i2s', dest='gen_i2s', action='',

should be

	parser.add_argument('--i2s', dest='gen_i2s', action='store_true',

Right?

-Takahiro AKASHI