fix windows cross-compilation to arm64

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1356bbb..82db598 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt

@@ -127,7 +127,7 @@
 set(MI_ARCH "unknown")
 if(CMAKE_SYSTEM_PROCESSOR MATCHES "^(x86|i[3456]86)$" OR CMAKE_GENERATOR_PLATFORM MATCHES "^(x86|Win32)$")
   set(MI_ARCH "x86")
-elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^(x86_64|x64|amd64|AMD64)$" OR CMAKE_GENERATOR_PLATFORM STREQUAL "x64" OR "x86_64" IN_LIST CMAKE_OSX_ARCHITECTURES) # must be before arm64
+elseif((CMAKE_SYSTEM_PROCESSOR MATCHES "^(x86_64|x64|amd64|AMD64)$" OR CMAKE_GENERATOR_PLATFORM STREQUAL "x64" OR "x86_64" IN_LIST CMAKE_OSX_ARCHITECTURES) AND NOT CMAKE_GENERATOR_PLATFORM STREQUAL "ARM64") # must be before arm64
   set(MI_ARCH "x64")
 elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^(aarch64|arm64|armv[89].?|ARM64)$" OR CMAKE_GENERATOR_PLATFORM STREQUAL "ARM64" OR "arm64" IN_LIST CMAKE_OSX_ARCHITECTURES)
   set(MI_ARCH "arm64")