wasapi: Fix build with Windows 8.1 SDK
With the Windows 8.1 SDK, the v1 of the AUDCLNT_STREAMOPTIONS enum is defined which only has NONE and RAW, so it's not only defined when AudioClient3 is available. Add a meson check for the symbol. This is not needed for Autotools because there we build against the MinGW audioclient.h which is still at v1 of the AudioClient interface.
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