Add BootImage to second DisplayBuffer during boot

include/PSX/System/IOPorts/gpu_io.hpp

@@ -106,6 +106,10 @@ namespace JabyEngine {
                 return {(0x02 << 24) | color.raw()};
             }
 
+            static constexpr GP0_t VRAM2VRAM_Blitting() {
+                return {(0b100u << 29)};
+            }
+
             static constexpr GP0_t CPU2VRAM_Blitting() {
                 return {(0b101u << 29)};
             }