ARM: OMAP2+: omap_device: use late_initcall_sync

If DEBUG_LL and earlyprintk are enabled, and omap-serial.c is compiled
as a module, the kernel boot hangs early as the clocks for serial port
are cut while earlyprintk still uses the port.

The problem is a race between the late_initcall for omap_device (which
idles devices that have no drivers) and the late_initcall in
kernel/printk.c which turns off the earlyconsole.   Any printks
that happen between this omap_device late initcall and the earlyconsole
late initcall will crash when accessing the UART.

The fix is to ensure the omap_device initcall happens after the
earlyconsole initcall.

Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>