sandbox: Use a text-based environment

Use a text file for the environment instead of the #define settings.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>

board/sandbox/sandbox.env

@@ -0,0 +1,25 @@
+stdin=serial
+#ifdef CONFIG_SANDBOX_SDL
+stdin+=,cros-ec-keyb,usbkbd
+#endif
+stdout=serial,vidconsole
+stderr=serial,vidconsole
+
+ethaddr=00:00:11:22:33:44
+eth2addr=00:00:11:22:33:48
+eth3addr=00:00:11:22:33:45
+eth4addr=00:00:11:22:33:48
+eth5addr=00:00:11:22:33:46
+eth6addr=00:00:11:22:33:47
+ipaddr=1.2.3.4
+
+/*
+ * These are used for distro boot which is not supported. But once bootmethod
+ * is provided these will be used again.
+ */
+bootm_size=0x10000000
+kernel_addr_r=0x1000000
+fdt_addr_r=0xc00000
+ramdisk_addr_r=0x2000000
+scriptaddr=0x1000
+pxefile_addr_r=0x2000