Change description of dev_boot_usb

Now indicates it covers SD as well (it did already, but now it's clearer).

BUG=chromium-os:17907
TEST=run `crossystem`; look at new descriptions

Change-Id: I4e4d8502b0dc5a29eb403039535b7512941ab4fa
Reviewed-on: http://gerrit.chromium.org/gerrit/4408
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Randall Spangler <rspangler@chromium.org>
diff --git a/utility/crossystem_main.c b/utility/crossystem_main.c
index c388af1..0c1d2fd 100644
--- a/utility/crossystem_main.c
+++ b/utility/crossystem_main.c
@@ -38,7 +38,7 @@
   {"cros_debug", 0, "OS should allow debug features"},
   {"dbg_reset", CAN_WRITE, "Debug reset mode request (writable)"},
   {"dev_boot_usb", CAN_WRITE,
-   "Enable developer mode boot from USB (writable)"},
+   "Enable developer mode boot from USB/SD (writable)"},
   {"devsw_boot", 0, "Developer switch position at boot"},
   {"devsw_cur",  0, "Developer switch current position"},
   {"ecfw_act", IS_STRING, "Active EC firmware"},