[util] Move design-related helper scripts to util/design

This also updates the paths and consolidates some subfunctions

Signed-off-by: Michael Schaffner <msf@opentitan.org>
diff --git a/hw/ip/otp_ctrl/doc/otp_ctrl_mmap.md b/hw/ip/otp_ctrl/doc/otp_ctrl_mmap.md
index 2ccdcbc..379c1b1 100644
--- a/hw/ip/otp_ctrl/doc/otp_ctrl_mmap.md
+++ b/hw/ip/otp_ctrl/doc/otp_ctrl_mmap.md
@@ -1,6 +1,6 @@
 <!--
 DO NOT EDIT THIS FILE DIRECTLY.
-It has been generated with hw/ip/otp_ctrl/util/gen-otp-mmap.py
+It has been generated with ./util/design/gen-otp-mmap.py
 -->
 
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