Move driverominit and sprintf to src/boot/ (#2105)

src/boot/sprintf.c

@@ -0,0 +1,32 @@
+#include "stdarg.h"
+#include "stdio.h"
+#include "string.h"
+#include "ultra64/xstdio.h"
+
+void* proutSprintf(void* dst, const char* fmt, size_t size) {
+    return (char*)memcpy(dst, fmt, size) + size;
+}
+
+int vsprintf(char* dst, const char* fmt, va_list args) {
+    int ret = _Printf(proutSprintf, dst, fmt, args);
+
+    if (ret > -1) {
+        dst[ret] = '\0';
+    }
+    return ret;
+}
+
+int sprintf(char* dst, const char* fmt, ...) {
+    int ret;
+    va_list args;
+    va_start(args, fmt);
+
+    ret = _Printf(proutSprintf, dst, fmt, args);
+    if (ret > -1) {
+        dst[ret] = '\0';
+    }
+
+    va_end(args);
+
+    return ret;
+}