added default.cfg to extra emu paks

skeleton/EXTRAS/Emus/rg35xx/MGBA.pak/default.cfg

@@ -0,0 +1,18 @@
+mgba_skip_bios = ON
+
+bind Up = UP
+bind Down = DOWN
+bind Left = LEFT
+bind Right = RIGHT
+bind Select = SELECT
+bind Start = START
+bind A Button = A
+bind B Button = B
+bind A Turbo = NONE:X
+bind B Turbo = NONE:Y
+bind L Button = L1
+bind R Button = R1
+bind L Turbo = NONE:L2
+bind R Turbo = NONE:R2
+bind More Sun = NONE:L3
+bind Less Sun = NONE:R3