test: Add some tests for setexpr

This command currently has no tests. Add some for basic assignment and the
integer operations.

Note that the default size for setexpr is ulong, which varies depending on
the build machine. So for sandbox on a 64-bit host, this means that the
default size is 64 bits.

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

test/cmd_ut.c

@@ -75,6 +75,8 @@ static struct cmd_tbl cmd_ut_sub[] = {
 	U_BOOT_CMD_MKENT(log, CONFIG_SYS_MAXARGS, 1, do_ut_log, "", ""),
 #endif
 	U_BOOT_CMD_MKENT(mem, CONFIG_SYS_MAXARGS, 1, do_ut_mem, "", ""),
+	U_BOOT_CMD_MKENT(setexpr, CONFIG_SYS_MAXARGS, 1, do_ut_setexpr, "",
+			 ""),
 #ifdef CONFIG_UT_TIME
 	U_BOOT_CMD_MKENT(time, CONFIG_SYS_MAXARGS, 1, do_ut_time, "", ""),
 #endif
@@ -153,6 +155,7 @@ static char ut_help_text[] =
 #ifdef CONFIG_UT_OVERLAY
 	"ut overlay [test-name]\n"
 #endif
+	"ut setexpr [test-name] - test setexpr command\n"
 #ifdef CONFIG_SANDBOX
 	"ut str - Basic test of string functions\n"
 #endif