Never add `+` to `cpu_flags` in `IUSE`

[hololeap]

pkgcheck scan gave me this warning:

dev-haskell/crypton
  BadDefaultUseFlags: version 1.0.4: bad default USE flags: '+cpu_flags_x86_aes', '+cpu_flags_x86_pclmul', '+cpu_flags_x86_rdrand'

Just remove the + from those flags. Those flags should not be enabled by default.

Edit:

The .cabal file has those flags enabled by default, and hackport is inheriting this behavior when it generates the ebuild. The +es should be removed manually every time hackport generates an ebuild for this package. (See pkgcore/pkgcheck#314 for why)

Originally posted by @hololeap in gentoo-haskell/gentoo-haskell#1782 (comment)

[hololeap]

Make it so that hackport does not automatically turn on + for cpu_flags_* in IUSE, even if the corresponding flag in the .cabal file is default = True.