x86_64: move serial port code to serialcon kext

kexts/drivers/tty/fbcon/vgacon.c

@@ -1,5 +1,4 @@
 #include <socks/tty.h>
-#include <arch/serial.h>
 #include <socks/libc/string.h>
 #include <socks/libc/ctype.h>
 #include <arch/ports.h>
@@ -42,7 +41,7 @@ static void move_vga_cursor(unsigned int x, unsigned int y)
 	outportb(VGA_PORT_DATA, (uint8_t)((offset >> 8) & 0xFF));
 }
 
-static void scroll_display()
+static void scroll_display(void)
 {
 	uint16_t *src = g_console_fb + k_console_width;
 	uint16_t *dst = g_console_fb;
@@ -78,8 +77,6 @@ static void handle_ctrl(int c)
 
 static void vgacon_putchar(int c)
 {
-	//serial_putchar(SERIAL_PORT_A, c);
-
 	if (iscntrl(c)) {
 		handle_ctrl(c);
 		return;