Move noise function declations to tr_common.h

tr_noise.c is in renderercommon directory, so declare them in header there too.

code/renderercommon/tr_common.h

@@ -72,6 +72,8 @@ extern cvar_t *r_stereoEnabled;
 
 qboolean	R_GetModeInfo( int *width, int *height, float *windowAspect, int mode );
 
+float R_NoiseGet4f( float x, float y, float z, float t );
+void  R_NoiseInit( void );
 
 /*
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