Update joy.c
Fixed missing volatile declaration (can broke code using GCC 6.3 with -03 optimization level)
#define JOY_TYPE_SHIFT 12
-static u8 joyType[8];
-static u16 joyState[8];
-static s16 joyAxisX[8];
-static s16 joyAxisY[8];
+static vu8 joyType[8];
+static vu16 joyState[8];
+static vs16 joyAxisX[8];
+static vs16 joyAxisY[8];
static u8 portSupport[2];
static u8 portType[2];
