Multiple changes:

- Makefile: fix linker script path
- irq.c: `irqN()` stubs
- irq.h: fix missing header
- isr.h/isr.c extern `interrupt_handlers`
- utils.c: remove duplicate `memcmp`

kernel/irq.h

@@ -1,6 +1,8 @@
 #ifndef IRQ_H
 #define IRQ_H
 
+#include "types.h"
+
 void irq_remap(void);
 void irq_install(void);
 void irq_handler(uint32_t int_num);