MDEV-9351 Fix CPU detection for TokuDB on FreeBSD

"x86_64" is "amd64" on FreeBSD

storage/tokudb/CMakeLists.txt

 SET(TOKUDB_VERSION 5.6.26-74.0)
 # PerconaFT only supports x86-64 and cmake-2.8.9+
-IF(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64" AND
-    NOT CMAKE_VERSION VERSION_LESS "2.8.9")
+IF(CMAKE_VERSION VERSION_LESS "2.8.9")
+  MESSAGE(STATUS "CMake 2.8.9 or higher is required by TokuDB")
+ELSEIF(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64" OR
+       CMAKE_SYSTEM_PROCESSOR STREQUAL "amd64")
 CHECK_CXX_SOURCE_COMPILES(
 "
 struct a {int b; int c; };
 struct a d = { .b=1, .c=2 };
 int main() { return 0; }
 " TOKUDB_OK)
-ELSE()
-  IF(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64"  AND
-     CMAKE_VERSION VERSION_LESS "2.8.9")
-    MESSAGE(STATUS "CMake 2.8.9 or higher is required by TokuDB")
-  ENDIF()
 ENDIF()
 
 IF(NOT TOKUDB_OK OR WITHOUT_TOKUDB OR WITHOUT_TOKUDB_STORAGE_ENGINE)