StreamADPCM: Convert into a namespace

No need to have a class with only static member functions

Source/Core/Core/HW/StreamADPCM.cpp

@@ -7,6 +7,9 @@
 #include "Common/MathUtil.h"
 #include "Core/HW/StreamADPCM.h"
 
+namespace StreamADPCM
+{
+
 // STATE_TO_SAVE (not saved yet!)
 static s32 histl1;
 static s32 histl2;
@@ -44,7 +47,7 @@ static s16 ADPDecodeSample(s32 bits, s32 q, s32& hist1, s32& hist2)
 	return (s16)cur;
 }
 
-void NGCADPCM::InitFilter()
+void InitFilter()
 {
 	histl1 = 0;
 	histl2 = 0;
@@ -52,7 +55,7 @@ void NGCADPCM::InitFilter()
 	histr2 = 0;
 }
 
-void NGCADPCM::DecodeBlock(s16 *pcm, const u8 *adpcm)
+void DecodeBlock(s16* pcm, const u8* adpcm)
 {
 	for (int i = 0; i < SAMPLES_PER_BLOCK; i++)
 	{
@@ -60,3 +63,5 @@ void NGCADPCM::DecodeBlock(s16 *pcm, const u8 *adpcm)
 		pcm[i * 2 + 1] = ADPDecodeSample(adpcm[i + (ONE_BLOCK_SIZE - SAMPLES_PER_BLOCK)] >> 4,  adpcm[1], histr1, histr2);
 	}
 }
+
+}