[CMAKE] Add support for using Linux compiler binaries on FreeBSD

cmake/arm-none-eabi-checks.cmake

@@ -33,9 +33,13 @@ function(arm_none_eabi_gcc_install)
     set(dist "")
     if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
         set(dist ${arm_none_eabi_win32})
-    elseif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux")
+    elseif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux" OR CMAKE_HOST_SYSTEM_NAME STREQUAL "FreeBSD")
+        if(NOT CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux")
+            message("-- no compiler binaries available for ${CMAKE_HOST_SYSTEM_NAME}, using Linux binaries as a fallback")
+        endif()
         host_uname_machine(machine)
-        if(machine STREQUAL "x86_64")
+        # Linux returns x86_64, FreeBSD returns amd64
+        if(machine STREQUAL "x86_64" OR machine STREQUAL "amd64")
             set(dist ${arm_none_eabi_linux_amd64})
         elseif(machine STREQUAL "aarch64")
             set(dist ${arm_none_eabi_linux_aarch64})