x86_64: move serial port code to serialcon kext

arch/x86_64/init.c

@@ -16,7 +16,6 @@
 #include <socks/machine/cpu.h>
 #include <socks/libc/stdio.h>
 #include <arch/vgacon.h>
-#include <arch/serial.h>
 
 #ifdef KEXT_NET_DOORSTUCK_SOCKS_ACPI
 #include <arch/acpi.h>
@@ -113,7 +112,6 @@ int ml_init(uintptr_t arg)
 #ifdef KEXT_NET_DOORSTUCK_SOCKS_FBCON
 	early_vgacon_init();
 #endif
-	serialcon_init(115200);
 	clock_calibrate(500);
 
 	print_kernel_banner();