dev/acpi: Implement uACPI kernel APIs

arch/x86_64/include/x86_64/apic.h

@@ -2,6 +2,9 @@
 
 #pragma once
 
+#include <zinnia/errno.h>
+#include <zinnia/initgraph.h>
+#include <zinnia/irq.h>
 #include <zinnia/mmio.h>
 #include <stdint.h>
 
@@ -81,3 +84,8 @@ void lapic_send_ipi(
 );
 
 void pic_disable();
+
+errno_t apic_alloc_vector(struct irq_line* line, uint8_t* out_vector, uint32_t* out_lapic);
+void apic_free_vector(uint8_t vector);
+
+INIT_EXTERN(ioapic_stage);