Add an emulated RTC device for sandbox, so that the 'date' command can be
used.
Signed-off-by: Simon Glass <sjg@chromium.org>
 
        aliases {
                eth5 = "/eth@90000000";
+               i2c0 = &i2c_0;
                pci0 = &pci;
+               rtc0 = &rtc_0;
        };
 
        chosen {
                num-gpios = <10>;
        };
 
-       i2c@0 {
+       i2c_0: i2c@0 {
                #address-cells = <1>;
                #size-cells = <0>;
                reg = <0 0>;
                                sandbox,size = <128>;
                        };
                };
+
+               rtc_0: rtc@43 {
+                       reg = <0x43>;
+                       compatible = "sandbox-rtc";
+                       emul {
+                               compatible = "sandbox,i2c-rtc";
+                       };
+               };
        };
 
        spi@0 {