boards: sltb001a + ikea_tradfri: adapt to new efm32 cpu

boards/ikea-tradfri/Makefile

-# tell the Makefile.base which module to build
 MODULE = board
 
 include $(RIOTBASE)/Makefile.base

boards/ikea-tradfri/Makefile.dep

@@ -2,4 +2,4 @@ ifneq (,$(filter saul_default,$(USEMODULE)))
     USEMODULE += saul_gpio
 endif
 
-include $(RIOTCPU)/efr32mg1p/Makefile.dep
+include $(RIOTCPU)/efm32/Makefile.dep

boards/ikea-tradfri/Makefile.features

@@ -9,4 +9,4 @@ FEATURES_PROVIDED += periph_uart
 # The board MPU family (used for grouping by the CI system)
 FEATURES_MCU_GROUP = cortex_m4_2
 
-include $(RIOTCPU)/efr32mg1p/Makefile.features
+include $(RIOTCPU)/efm32/Makefile.features

boards/ikea-tradfri/Makefile.include

 # define the cpu used by ikea-tradfri
-export CPU = efr32mg1p
+export CPU = efm32
 export CPU_MODEL = efr32mg1p132f256gm32
 
 # set default port depending on operating system

boards/sltb001a/Makefile

-# tell the Makefile.base which module to build
 MODULE = board
 
 include $(RIOTBASE)/Makefile.base

boards/sltb001a/Makefile.dep

@@ -7,4 +7,4 @@ endif
 # i2c is required for environmental sensors
 USEMODULE += periph_i2c
 
-include $(RIOTCPU)/efr32mg1p/Makefile.dep
+include $(RIOTCPU)/efm32/Makefile.dep

boards/sltb001a/Makefile.features

@@ -11,4 +11,4 @@ FEATURES_PROVIDED += periph_uart
 # The board MPU family (used for grouping by the CI system)
 FEATURES_MCU_GROUP = cortex_m4_2
 
-include $(RIOTCPU)/efr32mg1p/Makefile.features
+include $(RIOTCPU)/efm32/Makefile.features

boards/sltb001a/Makefile.include

 # define the cpu used by SLTB001A
-export CPU = efr32mg1p
+export CPU = efm32
 export CPU_MODEL = efr32mg1p132f256gm48
 
 # set default port depending on operating system