Add support of NUCLEO_F746ZG

Same variant than NUCLEO_F756ZG
The only difference between both is that F756 embed cryptographic accelerator AES and CRYP,
that are not currently supported by Arduino

Author: ABOSTM

boards.txt

@@ -46,6 +46,19 @@ Nucleo_144.menu.pnum.NUCLEO_F429ZI.build.product_line=STM32F429xx
 Nucleo_144.menu.pnum.NUCLEO_F429ZI.build.variant=NUCLEO_F429ZI
 Nucleo_144.menu.pnum.NUCLEO_F429ZI.build.cmsis_lib_gcc=arm_cortexM4lf_math
 
+# NUCLEO_F746ZG board
+Nucleo_144.menu.pnum.NUCLEO_F746ZG=Nucleo F746ZG
+Nucleo_144.menu.pnum.NUCLEO_F746ZG.node=NODE_F746ZG
+Nucleo_144.menu.pnum.NUCLEO_F746ZG.upload.maximum_size=1048576
+Nucleo_144.menu.pnum.NUCLEO_F746ZG.upload.maximum_data_size=327680
+Nucleo_144.menu.pnum.NUCLEO_F746ZG.build.mcu=cortex-m7
+Nucleo_144.menu.pnum.NUCLEO_F746ZG.build.flags.fp=-mfpu=fpv4-sp-d16 -mfloat-abi=hard
+Nucleo_144.menu.pnum.NUCLEO_F746ZG.build.board=NUCLEO_F746ZG
+Nucleo_144.menu.pnum.NUCLEO_F746ZG.build.series=STM32F7xx
+Nucleo_144.menu.pnum.NUCLEO_F746ZG.build.product_line=STM32F746xx
+Nucleo_144.menu.pnum.NUCLEO_F746ZG.build.variant=NUCLEO_F756ZG
+Nucleo_144.menu.pnum.NUCLEO_F746ZG.build.cmsis_lib_gcc=arm_cortexM7lfsp_math
+
 # NUCLEO_F756ZG board
 Nucleo_144.menu.pnum.NUCLEO_F756ZG=Nucleo F756ZG
 Nucleo_144.menu.pnum.NUCLEO_F756ZG.node=NODE_F756ZG