dm: tegra: Add platform data for the GPIO driver

Add platform data for the GPIO driver. It doesn't need to contain anything
since the GPIO driver will actually use information from the CONFIGs for
now. This merely serves to ensure that the GPIO driver is bound.

Signed-off-by: Simon Glass <sjg@chromium.org>

board/nvidia/common/board.c

@@ -6,6 +6,7 @@
  */
 
 #include <common.h>
+#include <dm.h>
 #include <ns16550.h>
 #include <linux/compiler.h>
 #include <asm/io.h>
@@ -43,6 +44,13 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+#ifdef CONFIG_SPL_BUILD
+/* TODO(sjg@chromium.org): Remove once SPL supports device tree */
+U_BOOT_DEVICE(tegra_gpios) = {
+	"gpio_tegra"
+};
+#endif
+
 const struct tegra_sysinfo sysinfo = {
 	CONFIG_TEGRA_BOARD_STRING
 };