cpu: always rely on stdio.inc.mk for default stdio selection

cpu/avr8_common/Makefile.dep

@@ -12,11 +12,6 @@ USEMODULE += malloc_thread_safe
 # The AVR-libc provides no strerror, so we provide it via tiny_strerror
 USEMODULE += tiny_strerror_as_strerror
 
-# the atmel port uses stdio_uart by default
-ifeq (,$(filter stdio_% slipdev_stdio,$(USEMODULE)))
-  USEMODULE += stdio_uart
-endif
-
 # static C++ constructors need guards for thread safe initialization
 ifneq (,$(filter cpp,$(FEATURES_USED)))
   USEMODULE += cxx_ctor_guards

cpu/esp_common/Makefile.dep

@@ -16,10 +16,6 @@ ifneq (,$(filter mtd,$(USEMODULE)))
   USEMODULE += periph_flash
 endif
 
-ifeq (,$(filter stdio_% slipdev_stdio,$(USEMODULE)))
-  USEMODULE += stdio_uart
-endif
-
 ifeq (xtensa,$(CPU_ARCH))
   USEMODULE += esp_xtensa
   USEMODULE += xtensa

makefiles/stdio.inc.mk

@@ -2,6 +2,7 @@ STDIO_MODULES = \
   slipdev_stdio \
   stdio_cdc_acm \
   stdio_ethos \
+  stdio_native \
   stdio_nimble \
   stdio_null \
   stdio_rtt \
@@ -10,10 +11,9 @@ STDIO_MODULES = \
   stdio_telnet \
   #
 
-ifneq (,$(filter newlib picolibc,$(USEMODULE)))
-  ifeq (,$(filter $(STDIO_MODULES),$(USEMODULE)))
-    USEMODULE += stdio_uart
-  endif
+# select stdio_uart if no other stdio module is slected
+ifeq (,$(filter $(STDIO_MODULES),$(USEMODULE)))
+  USEMODULE += stdio_uart
 endif
 
 ifneq (,$(filter stdio_cdc_acm,$(USEMODULE)))