fastboot: Update help text with respect to CMDLINE

This hunk of the patch was missed when using "b4" to apply the series.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/fastboot/Kconfig b/drivers/fastboot/Kconfig
index 58b0812..d6e2be0 100644
--- a/drivers/fastboot/Kconfig
+++ b/drivers/fastboot/Kconfig
@@ -12,6 +12,10 @@
 	  More information about the protocol and usecases:
 	  https://android.googlesource.com/platform/system/core/+/refs/heads/master/fastboot/
 
+	  Note that enabling CMDLINE is recommended since fastboot allows U-Boot
+	  commands to be executed on request. The CMDLINE option is required
+	  for anything other than simply booting the OS.
+
 config USB_FUNCTION_FASTBOOT
 	bool "Enable USB fastboot gadget"
 	depends on USB_GADGET