Remove unused export

Author: CasualPokePlayer

src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBA/LibmGBA.cs

@@ -187,9 +187,6 @@ public abstract bool BizSubAdvance(IntPtr ctx, Buttons keys, int[] vbuff, ref in
 		[BizImport(cc)]
 		public abstract void BizSetRegister(IntPtr ctx, int index, int value);
 
-		[BizImport(cc)]
-		public abstract ulong BizGetGlobalTime(IntPtr ctx);
-
 		[BizImport(cc)]
 		public abstract void BizWriteBus(IntPtr ctx, uint addr, byte val);