Fixes compiling of bluetrum/ab32vg1-ab-prougen

By implement stub my_printf and remove cconfig.h

Author: lygstate

bsp/bluetrum/ab32vg1-ab-prougen/cconfig.h

@@ -47,7 +47,10 @@ const uint8_t sysclk_index[] = {
 };
 
 sys_t sys = {0};
-void my_printf(const char *format, ...);
+
+void my_printf(const char *format, ...)
+{
+}
 
 static void delay_us(uint16_t nus)
 {