sandbox: Drop the deprecated 'sb' command

The old 'sb' command was deprecated in 2015 and replaced with 'host'.
Remove the remaining users and the command, so that the name is available
for other purposes.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/py/tests/test_fit.py b/test/py/tests/test_fit.py
index 34696e9..49d6fea 100755
--- a/test/py/tests/test_fit.py
+++ b/test/py/tests/test_fit.py
@@ -99,15 +99,15 @@
 # then run the 'bootm' command, then save out memory from the places where
 # we expect 'bootm' to write things. Then quit.
 base_script = '''
-sb load hostfs 0 %(fit_addr)x %(fit)s
+host load hostfs 0 %(fit_addr)x %(fit)s
 fdt addr %(fit_addr)x
 bootm start %(fit_addr)x
 bootm loados
-sb save hostfs 0 %(kernel_addr)x %(kernel_out)s %(kernel_size)x
-sb save hostfs 0 %(fdt_addr)x %(fdt_out)s %(fdt_size)x
-sb save hostfs 0 %(ramdisk_addr)x %(ramdisk_out)s %(ramdisk_size)x
-sb save hostfs 0 %(loadables1_addr)x %(loadables1_out)s %(loadables1_size)x
-sb save hostfs 0 %(loadables2_addr)x %(loadables2_out)s %(loadables2_size)x
+host save hostfs 0 %(kernel_addr)x %(kernel_out)s %(kernel_size)x
+host save hostfs 0 %(fdt_addr)x %(fdt_out)s %(fdt_size)x
+host save hostfs 0 %(ramdisk_addr)x %(ramdisk_out)s %(ramdisk_size)x
+host save hostfs 0 %(loadables1_addr)x %(loadables1_out)s %(loadables1_size)x
+host save hostfs 0 %(loadables2_addr)x %(loadables2_out)s %(loadables2_size)x
 '''
 
 @pytest.mark.boardspec('sandbox')