scripts: kconfig: functions: add dt_compat_enabled_num function

Add dt_compat_enabled_num Kconfig helper function for counting the number
of compatible nodes with status okay.

Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>

doc/build/kconfig/preprocessor-functions.rst

@@ -42,6 +42,7 @@ while the ``*_hex`` version returns a hexadecimal value starting with ``0x``.
    $(dt_compat_any_has_prop,<compatible string>,<prop>[,<value>])
    $(dt_compat_any_on_bus,<compatible string>,<prop>)
    $(dt_compat_enabled,<compatible string>)
+   $(dt_compat_enabled_num,<compatible string>)
    $(dt_compat_on_bus,<compatible string>,<bus>)
    $(dt_gpio_hogs_enabled)
    $(dt_has_compat,<compatible string>)

scripts/kconfig/kconfigfunctions.py

@@ -771,6 +771,17 @@ def dt_compat_enabled(kconf, _, compat):
     return "y" if compat in edt.compat2okay else "n"
 
 
+def dt_compat_enabled_num(kconf, _, compat):
+    """
+    This function takes a 'compat' and the returns number of status "okay"
+    compatible nodes in the EDT.
+    """
+    if doc_mode or edt is None:
+        return "0"
+
+    return str(len(edt.compat2okay[compat]))
+
+
 def dt_compat_on_bus(kconf, _, compat, bus):
     """
     This function takes a 'compat' and returns "y" if we find an enabled
@@ -1074,6 +1085,7 @@ def inc_dec(kconf, name, *args):
 functions = {
         "dt_has_compat": (dt_has_compat, 1, 1),
         "dt_compat_enabled": (dt_compat_enabled, 1, 1),
+        "dt_compat_enabled_num": (dt_compat_enabled_num, 1, 1),
         "dt_compat_on_bus": (dt_compat_on_bus, 2, 2),
         "dt_compat_any_has_prop": (dt_compat_any_has_prop, 2, 3),
         "dt_compat_any_not_has_prop": (dt_compat_any_not_has_prop, 2, 2),