added CMake host processor check to appropriately set WOLFSSL_AARCH64_BUILD on M1 macs

Author: bigbrett

CMakeLists.txt

@@ -1577,8 +1577,11 @@ endif()
 
 # TODO: - Fast huge math
 
+# Set processor-specific build macros
 if("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "x86_64|AMD64")
     list(APPEND WOLFSSL_DEFINITIONS "-DWOLFSSL_X86_64_BUILD")
+elseif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "aarch64|arm64")
+    list(APPEND WOLFSSL_DEFINITIONS "-DWOLFSSL_AARCH64_BUILD")
 endif()
 
 # SP math all