Fix POLL* definitions per Dolphin

[endrift]

Cf. https://github.com/dolphin-emu/dolphin/blob/master/Source/Core/Core/IOS/Network/IP/Top.cpp#L608-L609
These #defines don't affect lwip/GC networking at all. The POLLIN mask is defined per POSIX:

[The POLLIN] flag shall be equivalent to POLLRDNORM | POLLRDBAND.

[mtheall]

I don't buy that this "don't affect lwip/GC networking at all." Aren't these the flags that you would plug into pollsd::events/revents? I would be more convinced if you showed evidence that the current flags are wrong when running on hardware.

The note about POSIX seems like a red herring. Is it expected that the official library strictly adheres to POSIX?

[endrift]

The reason it doesn't affect lwip is because lwip doesn't implement net_poll: https://github.com/devkitPro/libogc/search?q=net_poll&unscoped_q=net_poll