cpu: stm32: reorganize Makefile.features

cpu/stm32_common/Makefile.features

+FEATURES_PROVIDED += periph_cpuid
+
+ifneq (,$(filter $(BOARDS_WITHOUT_HWRNG),$(BOARD)))
+  FEATURES_PROVIDED := $(filter-out periph_hwrng,$(FEATURES_PROVIDED))
+endif
+
+-include $(RIOTCPU)/cortexm_common/Makefile.features

cpu/stm32f0/Makefile.features

+ifeq (,$(filter nucleo32-f031,$(BOARD)))
+  FEATURES_PROVIDED += periph_flashpage
+endif
+
+-include $(RIOTCPU)/stm32_common/Makefile.features

cpu/stm32f1/Makefile.features

+FEATURES_PROVIDED += periph_flashpage
 FEATURES_PROVIDED += periph_pm
+
+-include $(RIOTCPU)/stm32_common/Makefile.features

cpu/stm32f2/Makefile.features

+FEATURES_PROVIDED += periph_hwrng
 FEATURES_PROVIDED += periph_pm
+
+-include $(RIOTCPU)/stm32_common/Makefile.features

cpu/stm32f3/Makefile.features

+-include $(RIOTCPU)/stm32_common/Makefile.features

cpu/stm32f4/Makefile.features

+FEATURES_PROVIDED += periph_hwrng
 FEATURES_PROVIDED += periph_pm
+
+# the granularity of provided feature definition for STMs is currently by CPU
+# sub-family (e.g., stm32f[1234]).  Unfortunately, only some of e.g., the
+# stm32f4 have an RNG peripheral.  As during evaluation of the features , no
+# CPU variable is available, we need to filter by board.
+#
+BOARDS_WITHOUT_HWRNG += nucleo-f401
+BOARDS_WITHOUT_HWRNG += nucleo-f411
+BOARDS_WITHOUT_HWRNG += nucleo-f446
+BOARDS_WITHOUT_HWRNG += nucleo144-f446
+
+-include $(RIOTCPU)/stm32_common/Makefile.features

cpu/stm32f7/Makefile.features

+FEATURES_PROVIDED += periph_hwrng
+-include $(RIOTCPU)/stm32_common/Makefile.features

cpu/stm32l0/Makefile.features

+FEATURES_PROVIDED += periph_hwrng
+
+BOARDS_WITHOUT_HWRNG += nucleo32-l031
+
+-include $(RIOTCPU)/stm32_common/Makefile.features

cpu/stm32l1/Makefile.features

+-include $(RIOTCPU)/stm32_common/Makefile.features

cpu/stm32l4/Makefile.features

+FEATURES_PROVIDED += periph_hwrng
+
+-include $(RIOTCPU)/stm32_common/Makefile.features