build: Fix regression in "ARMv8 CRC32 intrinsics" test

The `vmull_p64` is a part of the Crypto extensions from the ACLE. They
are optional extensions, so they get enabled with a `+crypto` for
architecture flags.

Author: hebasto

configure.ac

@@ -579,7 +579,7 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 CXXFLAGS="$TEMP_CXXFLAGS"
 
 # ARM
-AX_CHECK_COMPILE_FLAG([-march=armv8-a+crc], [ARM_CRC_CXXFLAGS="-march=armv8-a+crc"], [], [$CXXFLAG_WERROR])
+AX_CHECK_COMPILE_FLAG([-march=armv8-a+crc+crypto], [ARM_CRC_CXXFLAGS="-march=armv8-a+crc+crypto"], [], [$CXXFLAG_WERROR])
 AX_CHECK_COMPILE_FLAG([-march=armv8-a+crypto], [ARM_SHANI_CXXFLAGS="-march=armv8-a+crypto"], [], [$CXXFLAG_WERROR])
 
 TEMP_CXXFLAGS="$CXXFLAGS"