cmd: Update the memory-search command

Add various fixes and improvements to this command that were missed in
the original version. Unfortunately I forgot to send v2.

- Fix Kconfig name
- Use a separate variable for the remaining search length
- Correct a minor bug
- Move into a separate test suite
- Add -q flag to the 'quiet' test to test operation when console is enabled
- Enable the feature for sandbox

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

test/cmd_ut.c

@@ -74,6 +74,7 @@ static struct cmd_tbl cmd_ut_sub[] = {
 #ifdef CONFIG_UT_LOG
 	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, "", ""),
 #ifdef CONFIG_UT_TIME
 	U_BOOT_CMD_MKENT(time, CONFIG_SYS_MAXARGS, 1, do_ut_time, "", ""),
 #endif
@@ -145,6 +146,7 @@ static char ut_help_text[] =
 #ifdef CONFIG_UT_LOG
 	"ut log [test-name] - test logging functions\n"
 #endif
+	"ut mem [test-name] - test memory-related commands\n"
 #ifdef CONFIG_UT_OPTEE
 	"ut optee [test-name]\n"
 #endif