ARM: OMAP2+: adjust the location of put_device() call in omapdss_init_of

This was found by coccicheck:
./arch/arm/mach-omap2/display.c, 272, 1-7, ERROR missing put_device;
call of_find_device_by_node on line 258, but without a corresponding
object release within this function.

Move the put_device() call before the if judgment.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Ye Guojin <ye.guojin@zte.com.cn>
Signed-off-by: Tony Lindgren <tony@atomide.com>