Fixed include dependencies

src/pic.c

@@ -5,7 +5,7 @@ uint8_t pic_read(uint16_t pic)
 {
     if(pic>1)
     {
-	return;
+	return 0;
     }
     uint16_t reg = (pic==0)? PIC1_REG_DATA:PIC2_REG_DATA;
     return inb(reg);

src/pit.c

 #include "pit.h"
 #include "pic.h"
 #include "idt.h"
+#include "asm.h"
 
 static volatile uint32_t _pit_ticks = 0;
 static bool _pit_is_init = false;