• Integrate completely with bsd.wx.mk.
• Use ARCH instead of MACHINE_ARCH (will possibly allow cross-compilation).
• Rename local WX_VERSION since it is a variable defined in bsd.wx.mk.
• Remove BROKEN for 4.x since bsd.wx.mk takes care of it when WX_UNICODE is defined.

PR: ports/105492
Submitted by: alepulver
Approved by: Denis Barov <dindin@dindin.ru> (maintainer)