syslinux.bbclass: Fix default serial port string

The default value of SYSLINUX_SERIAL_TTY is not correct.

It should be console=ttyS0,115200 else the boot string generated in the syslinux menus for the serial choice is not correct. The kernel boot parameters will get set to:

/vmlinuz initrd=/initrd LABEL=boot root=/dev/ram0 ttyS0,115200

Note that the above is missing the "console="

The default value will now work the same as the value found in grub-efi.bbclass.

---
 meta/classes/syslinux.bbclass |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 944bd92..2a5b766 100644
@@ -27,7 +27,7 @@ SYSLINUXDIR = "/"
 # a console=...some_tty...
 SYSLINUX_DEFAULT_CONSOLE ?= ""
 SYSLINUX_SERIAL ?= "0 115200"
-SYSLINUX_SERIAL_TTY ?= "ttyS0,115200"
+SYSLINUX_SERIAL_TTY ?= "console=ttyS0,115200"
 ISO_BOOTIMG = "isolinux/isolinux.bin"
 ISO_BOOTCAT = "isolinux/boot.cat"
 MKISOFS_OPTIONS = "-no-emul-boot -boot-load-size 4 -boot-info-table"

1.7.9.5