memory: omap-gpmc: make dts snippet include semicolon

In the device tree each property must be terminated with a semicolon, so
include them in the output for easier cut-n-paste.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>