scripts: size_report: Add a depth parameter to CMakeLists.txt

The parameter can be used to limit the ram and rom reports to a
certain depth.  The resulting graphs with depths of e.g. 3 or 4 are
visually easier to grasp.

Signed-off-by: Detlev Zundel <dzu@member.fsf.org>

cmake/reports/CMakeLists.txt

@@ -2,6 +2,7 @@
 
 set(flag_for_ram_report ram)
 set(flag_for_rom_report rom)
+set(report_depth 99)
 
 foreach(report ram_report rom_report)
   add_custom_target(
@@ -12,6 +13,7 @@ foreach(report ram_report rom_report)
     -z ${ZEPHYR_BASE}
     -o ${CMAKE_BINARY_DIR}
     --json ${CMAKE_BINARY_DIR}/${flag_for_${report}}.json
+    -d ${report_depth}
     ${flag_for_${report}}
     DEPENDS ${logical_target_for_zephyr_elf}
             $<TARGET_PROPERTY:zephyr_property_target,${report}_DEPENDENCIES>