boards/Makefile.include: remove duplicate includes

Includes of $(CPU)/include and $(BOARD)/include and already added in the
main Makefile.include.

Verification:

There are no common headers names between boards and cpus.
Except native that has a 'periph_conf.h' in cpu instead of being in board.

boards/arduino-mkr1000/Makefile.include

@@ -5,6 +5,3 @@ ifeq ($(PROGRAMMER),jlink)
 endif
 
 include $(RIOTBOARD)/common/arduino-mkr/Makefile.include
-
-# add arduino-mkr1000 include path
-INCLUDES += -I$(RIOTBOARD)/$(BOARD)/include

boards/arduino-mkrfox1200/Makefile.include

@@ -5,6 +5,3 @@ ifeq ($(PROGRAMMER),jlink)
 endif
 
 include $(RIOTBOARD)/common/arduino-mkr/Makefile.include
-
-# add arduino-mkrfox1200 include path
-INCLUDES += -I$(RIOTBOARD)/$(BOARD)/include

boards/arduino-mkrzero/Makefile.include

@@ -5,6 +5,3 @@ ifeq ($(PROGRAMMER),jlink)
 endif
 
 include $(RIOTBOARD)/common/arduino-mkr/Makefile.include
-
-# add arduino-mkrzero include path
-INCLUDES += -I$(RIOTBOARD)/$(BOARD)/include

boards/iotlab-a8-m3/Makefile.include

 USEMODULE += boards_common_iotlab
 
 include $(RIOTBOARD)/common/iotlab/Makefile.include
-
-# add iotlab-a8-m3 include path
-INCLUDES += -I$(RIOTBOARD)/$(BOARD)/include

boards/iotlab-m3/Makefile.include

 USEMODULE += boards_common_iotlab
 
 include $(RIOTBOARD)/common/iotlab/Makefile.include
-
-# add iotlab-m3 include path
-INCLUDES += -I$(RIOTBOARD)/$(BOARD)/include

boards/mips-malta/Makefile.include

 export CPU = mips32r2_generic
-export INCLUDES += -I$(RIOTBOARD)/$(BOARD)/include/
 #export USE_HARD_FLOAT = 1
 export USE_DSP = 1
 export USE_UHI_SYSCALLS = 1

boards/nz32-sc151/Makefile.include

@@ -17,7 +17,5 @@ HEXFILE = $(BINFILE)
 export FFLAGS = -d $(ID) -a 0 -s 0x08000000:leave -D "$(HEXFILE)"
 export TERMFLAGS = -p $(PORT)
 
-export INCLUDES += -I$(RIOTCPU)/$(CPU)/include/ -I$(RIOTBOARD)/$(BOARD)/include/
-
 # setup serial terminal
 include $(RIOTMAKE)/tools/serial.inc.mk

boards/pic32-clicker/Makefile.include

 export CPU = mips_pic32mx
 export CPU_MODEL=p32mx470f512h
-export INCLUDES += -I$(RIOTBOARD)/$(BOARD)/include/
 export APPDEPS += $(RIOTCPU)/$(CPU)/$(CPU_MODEL)/$(CPU_MODEL).S
 export USE_UHI_SYSCALLS = 1

boards/pic32-wifire/Makefile.include

 export CPU = mips_pic32mz
 export CPU_MODEL=p32mz2048efg100
-export INCLUDES += -I$(RIOTBOARD)/$(BOARD)/include/
 export APPDEPS += $(RIOTCPU)/$(CPU)/$(CPU_MODEL)/$(CPU_MODEL).S
 export USE_UHI_SYSCALLS = 1

boards/spark-core/Makefile.include

@@ -14,8 +14,6 @@ export RESET = # dfu-util has no support for resetting the device
 HEXFILE = $(BINFILE)
 export FFLAGS = -d 1d50:607f -a 0 -s 0x08005000:leave -D "$(HEXFILE)"
 
-export INCLUDES += -I$(RIOTCPU)/$(CPU)/include/ -I$(RIOTBOARD)/$(BOARD)/include/
-
 # Skip the space needed by the embedded bootloader
 export ROM_OFFSET ?= 0x5000