sound/s_dsp.cpp: Updates/Cleanups (#13488)

* sound/s_dsp.cpp: Fix pitch modulation emulation, Fix save state support

reference: https://snes.nesdev.org/wiki/SNESdev_Wiki

* sound/s_dsp.cpp: Fix indent

* s_dsp.cpp: Reduce unnecessary lines, Fix typenames

* sound/s_dsp.cpp: More std::clamp uses, Use BIT for single bit flags

* sound/s_dsp.cpp: Fix input clock, Fix indent, Use lowercase hexadecimal values, Use reference for voice state

reference: https://snes.nesdev.org/wiki/S-SMP

* sound/s_dsp.cpp: Use logmacro.h for logging, Use BIT for single bit flags

Author: cam900