multimedia/libtheora: fix build on armv7
- switch to gmake, which is needed for arm-specific pattern rules
- depend on Perl, which is needed to run an assembly-mangling script
- depend on GNU as, which is needed for pre-UAL style ARM menmonics
- switch to gitlab tarball as the official tarball is missing some important files
- turn static REINPLACE_CMD into patch files were possible
- make sure "make check" actually runs test suite
- add the usual elf_aux_info() polyfill
- enable X86 assembly code (builds fine, passes test suite)
MFH: 2025Q4
Approved by: mmel (multimedia)
Reported by: mmel