gpio: Build the da8xx_gpio code for the davinci644x device

The differences include the number of GPIOs and that one is
not required to set the pinmux on request.

Signed-off-by: Holger Hans Peter Freyther <holger@freyther.de>
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 2d97b4f..9df1e26 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -39,6 +39,7 @@
 COBJS-$(CONFIG_SPEAR_GPIO)	+= spear_gpio.o
 COBJS-$(CONFIG_TEGRA_GPIO)	+= tegra_gpio.o
 COBJS-$(CONFIG_DA8XX_GPIO)	+= da8xx_gpio.o
+COBJS-$(CONFIG_DM644X_GPIO)	+= da8xx_gpio.o
 COBJS-$(CONFIG_ALTERA_PIO)	+= altera_pio.o
 COBJS-$(CONFIG_MPC83XX_GPIO)	+= mpc83xx_gpio.o
 COBJS-$(CONFIG_SH_GPIO_PFC)	+= sh_pfc.o