fix build failure in Apple M1

[rusydi]

Running make in Apple M1 produces the following build failure. This is due to the checking the availability of x86 vector instructions in x86_cpuid.c

[ 25%] Building C object src/CMakeFiles/feslite.dir/naive_eval.c.o
[ 25%] Building C object src/CMakeFiles/feslite.dir/generic_eval32.c.o
[ 25%] Building C object src/CMakeFiles/feslite.dir/generic_minimal.c.o
[ 25%] Building C object src/CMakeFiles/feslite.dir/feslite.c.o
[ 37%] Building C object src/CMakeFiles/feslite.dir/generic_1x32.c.o
[ 37%] Building C object src/CMakeFiles/feslite.dir/generic_2x16.c.o
[ 50%] Building C object src/CMakeFiles/feslite.dir/generic_4x16.c.o
[ 50%] Building C object src/CMakeFiles/feslite.dir/generic_2x32.c.o
[ 56%] Building C object src/CMakeFiles/feslite.dir/x86_cpuid.c.o
/Users/rusydi/CLionProjects/libfes-lite/src/x86_cpuid.c:18:25: error: invalid output constraint '+b' in asm
    __asm__ ( "cpuid" : "+b" (ebx),
                        ^
1 error generated.
make[2]: *** [src/CMakeFiles/feslite.dir/x86_cpuid.c.o] Error 1
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [src/CMakeFiles/feslite.dir/all] Error 2
make: *** [all] Error 2