ADLMIDI, EDMIDI, OPNMIDI: use GNU90 standard

[ds-sloth]

Fixes 3DS build on some versions of devkitPro toolchain

[Wohlstand]

Don't apply these fixes here. Apply them to original repositories instead. And here just run the _common/update_libs.sh (and, discard GME changes, because it reverts my fix that awaiting the merge to the mainstream repo).

[Wohlstand]

Apply to these repos:

• https://github.com/Wohlstand/libADLMIDI
• https://github.com/Wohlstand/libOPNMIDI
• https://github.com/Wohlstand/libEDMIDI

[Wohlstand]

I applied these changes to all original repos, and now they are here: https://github.com/WohlSoft/AudioCodecs/commit/e6f5414b4718d0a21c9ef0af9c887d65c5bc1c30