Further parse AHCI information.

Send an IDENTIFY command to each drive and set up a hook to handle
interrupts.

sys/denali/denali.cpp

@@ -1,8 +1,13 @@
+#include <mammoth/debug.h>
 #include <stdint.h>
 
 #include "ahci/ahci_driver.h"
 
 int main(uint64_t bootstrap_cap) {
   AhciDriver driver;
-  return driver.Init();
+  RET_ERR(driver.Init());
+
+  while (1) {
+  };
+  return 0;
 }