omap: Update omap2plus_defconfig to use ttyO instead ttyS

With the omap-serial the device has changed from ttyS to ttyO as
the system may have both omap-serial and 8250 ports.

Note that systems using omap-serial need to be updated to use ttyO[012]
instead of ttyS[012] in the bootloader, CONFIG_CMDLINE, /etc/inittab,
and the root file system with mknod. Also you may need to add ttyO[012]
to /etc/securetty.
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/configs/omap2plus_defconfig

@@ -63,7 +63,7 @@ CONFIG_AEABI=y
 CONFIG_LEDS=y
 CONFIG_ZBOOT_ROM_TEXT=0x0
 CONFIG_ZBOOT_ROM_BSS=0x0
-CONFIG_CMDLINE="root=/dev/mmcblk0p2 rootwait console=ttyS2,115200"
+CONFIG_CMDLINE="root=/dev/mmcblk0p2 rootwait console=ttyO2,115200"
 CONFIG_KEXEC=y
 CONFIG_FPE_NWFPE=y
 CONFIG_VFP=y