sandbox: Fix up building for of-platdata

There is no devicetree with of-platdata. Update a few uclasses to allow
them to be built for sandbox_spl. Also drop the i2c-gpio from SPL to avoid
build errors, since it does not support of-platdata.

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

drivers/i2c/Makefile

@@ -6,7 +6,7 @@ obj-$(CONFIG_DM_I2C) += i2c-uclass.o
 ifdef CONFIG_ACPIGEN
 obj-$(CONFIG_DM_I2C) += acpi_i2c.o
 endif
-obj-$(CONFIG_DM_I2C_GPIO) += i2c-gpio.o
+obj-$(CONFIG_$(SPL_)DM_I2C_GPIO) += i2c-gpio.o
 obj-$(CONFIG_$(SPL_)I2C_CROS_EC_TUNNEL) += cros_ec_tunnel.o
 obj-$(CONFIG_$(SPL_)I2C_CROS_EC_LDO) += cros_ec_ldo.o
 

drivers/i2c/i2c-emul-uclass.c

@@ -76,7 +76,9 @@ UCLASS_DRIVER(i2c_emul) = {
 UCLASS_DRIVER(i2c_emul_parent) = {
 	.id		= UCLASS_I2C_EMUL_PARENT,
 	.name		= "i2c_emul_parent",
+#if !CONFIG_IS_ENABLED(OF_PLATDATA)
 	.post_bind	= dm_scan_fdt_dev,
+#endif
 };
 
 static const struct udevice_id i2c_emul_parent_ids[] = {

drivers/rtc/rtc-uclass.c

@@ -174,5 +174,7 @@ int rtc_write32(struct udevice *dev, unsigned int reg, u32 value)
 UCLASS_DRIVER(rtc) = {
 	.name		= "rtc",
 	.id		= UCLASS_RTC,
+#if !CONFIG_IS_ENABLED(OF_PLATDATA)
 	.post_bind	= dm_scan_fdt_dev,
+#endif
 };