cmake: targets: usage: add missing custom targets

Added pahole, puncover and footprint to the target documentation.

Fixes: #77563

Signed-off-by: Florian Grandel <fgrandel@code-for-humans.de>

cmake/usage/usage.cmake

@@ -25,8 +25,11 @@ message("  flash        - Run \"west flash\"")
 message("  debug        - Run \"west debug\"")
 message("  debugserver  - Run \"west debugserver\" (or start GDB server on port 1234 for QEMU targets)")
 message("  attach       - Run \"west attach\"")
+message("  pahole       - Report struct padding (requires the pahole program)")
+message("  puncover     - Local web server to view RAM, ROM and stack usage (requires puncover pip module)")
 message("  ram_report   - Build and create RAM usage report")
 message("  rom_report   - Build and create ROM usage report")
+message("  footprint    - Create JSON RAM/ROM usage report in the build directory")
 message("  initlevels   - Display the initialization sequence")
 message("  boards       - Display supported boards")
 message("  shields      - Display supported shields")