Update Audio Macros

Information: Our current audio macros preclude the definition of root
key and pan (applicable when used in drumsets, aka "keysplit_all") for
GB channels. However, this functionality does exist in m4a--Pokemon
Emerald just happens not to use it. However, for the sake of people
working with custom music, I believe these values should be modifiable
by users.

Additionally, given the recent events that have occurred with this repo,
I would like to make something fully clear: I have indeed looked at the
GBA SDK before, which contains notes on how these sounds are defined;
therefore, I cannot blame you if you reject this PR on the grounds that
the information is "tainted." However, this information is readily
available and matches the same macros used for directsound--it's hardly
information that one would need the source to know.

sound/voicegroups/voicegroup140.inc

@@ -1,7 +1,7 @@
 	.align 2
 voicegroup140:: @ 86A41D4
 	voice_keysplit_all voicegroup001  @ 86A41D4
-	voice_square_1 0, 2, 0, 2, 3, 1  @ 86A41E0
-	voice_square_2_alt 2, 0, 2, 3, 1  @ 86A41EC
-	voice_programmable_wave_alt ProgrammableWaveData_86B4870, 0, 7, 15, 0  @ 86A41F8
+	voice_square_1 60, 0, 0, 2, 0, 2, 3, 1  @ 86A41E0
+	voice_square_2_alt 60, 0, 2, 0, 2, 3, 1  @ 86A41EC
+	voice_programmable_wave_alt 60, 0, ProgrammableWaveData_86B4870, 0, 7, 15, 0  @ 86A41F8