[rp2040] check delay tune

Author: andryblack

examples/generic/delay/project.xml

@@ -17,6 +17,7 @@
   <!-- <extends>modm:nucleo-l432kc</extends> -->
   <!-- <extends>modm:nucleo-l476rg</extends> -->
   <!-- <extends>modm:samd21-mini</extends> -->
+  <!-- <extends>modm:rp-pico</extends> -->
   <options>
     <option name="modm:build:build.path">../../../build/generic/delay</option>
     <option name="modm:io:with_printf">true</option>

src/modm/platform/core/rp/module.lb

@@ -42,9 +42,9 @@ def build(env):
     env.template("startup_platform.cpp.in")
 
     # delay code that must be tuned for each family
-    # (cycles per loop, setup cost in loops, max cpu frequency)
+    # (cycles per loop, setup cost in loops)
     tuning = {
-        "rp20": (3, 4,  48), # @todo
+        "rp20": (3, 4)
     }["{}{}".format(target.platform,target.family)]
 
     # us_shift is an optimization to limit error via fractional math