sunxi: Do not build i2c support when we've no i2c controllers

This fixes the following errors being printed during boot:

Error, wrong i2c adapter 0 max 0 possible
Error, wrong i2c adapter 0 max 0 possible

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

include/configs/sunxi-common.h

@@ -195,14 +195,15 @@
 #define CONFIG_SPL_I2C_SUPPORT
 #endif
 
-#define CONFIG_SYS_I2C
 #if defined CONFIG_I2C0_ENABLE || defined CONFIG_I2C1_ENABLE || \
     defined CONFIG_I2C2_ENABLE || defined CONFIG_I2C3_ENABLE || \
     defined CONFIG_I2C4_ENABLE
+#define CONFIG_SYS_I2C
 #define CONFIG_SYS_I2C_MVTWSI
-#endif
 #define CONFIG_SYS_I2C_SPEED		400000
 #define CONFIG_SYS_I2C_SLAVE		0x7f
+#define CONFIG_CMD_I2C
+#endif
 
 #if defined CONFIG_VIDEO_LCD_PANEL_I2C && !(defined CONFIG_SPL_BUILD)
 #define CONFIG_SYS_I2C_SOFT
@@ -222,8 +223,6 @@ extern int soft_i2c_gpio_scl;
 #define CONFIG_VIDEO_LCD_I2C_BUS	-1 /* NA, but necessary to compile */
 #endif
 
-#define CONFIG_CMD_I2C
-
 /* PMU */
 #if defined CONFIG_AXP152_POWER || defined CONFIG_AXP209_POWER || defined CONFIG_AXP221_POWER
 #define CONFIG_SPL_POWER_SUPPORT