add interrupt init code (and increase rtc tick rate)

sw/kernel/kernel.c

@@ -1,8 +1,14 @@
 #include <conio.h>
 #include "devices/interrupt_controller.h"
+#include "interrupts/interrupt.h"
 #include "devices/rtc.h"
 
 
+void handle_rtc_interrupt() {
+    cputs("In IRQ interrupt!\n");
+    asm volatile ("rti");
+}
+
 int main() {
 
     cputs("Kernel\n");
@@ -19,6 +25,8 @@ int main() {
     cputs("Initialize RTC\n");
     init_rtc();
 
+    register_irq(&handle_rtc_interrupt, 0);
+
     // cputs("Initialize Serial\n");
     // // init_serial();
     // enable_irq(2, IRQ_EDGE);
@@ -26,4 +34,4 @@ int main() {
     while(1);
 
     return 0;
-}
+}