libvpx*: fix patch which fails to apply after update

[barracuda156]

Description

Fix the build broken by a patch not being rebased. Apply it unconditionally (it only deals with powerpc).
Drop some unneeded stuff in the portfile like redundant blacklisting and duplicate configure args.

Type(s)

• bugfix
• enhancement
• security fix

Tested on

macOS 10.6
Xcode 3.2

Verification

Have you

• followed our Commit Message Guidelines?
• squashed and minimized your commits?
• checked that there aren't other open pull requests for the same change?
• referenced existing tickets on Trac with full URL in commit message?
• checked your Portfile with port lint?
• tried existing tests with sudo port test?
• tried a full install with sudo port -vst install?
• tested basic functionality of all binary files?
• checked that the Portfile's most important variants haven't been broken?

[macportsbot]

Notifying maintainers:
@mascguy for port libvpx-devel, libvpx.