selftests: x86: sysret_ss_attrs doesn't build on a PIE build

sysret_ss_attrs fails to compile leading x86 test run to fail on systems
configured to build using PIE by default. Add -no-pie fix it.

Relocation might still fail if relocated above 4G. For now this change
fixes the build and runs x86 tests.

tools/testing/selftests/x86$ make
gcc -m64 -o .../tools/testing/selftests/x86/single_step_syscall_64 -O2
-g -std=gnu99 -pthread -Wall  single_step_syscall.c -lrt -ldl
gcc -m64 -o .../tools/testing/selftests/x86/sysret_ss_attrs_64 -O2 -g
-std=gnu99 -pthread -Wall  sysret_ss_attrs.c thunks.S -lrt -ldl
/usr/bin/ld: /tmp/ccS6pvIh.o: relocation R_X86_64_32S against `.text'
can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: final link failed: Nonrepresentable section on output
collect2: error: ld returned 1 exit status
Makefile:49: recipe for target
'.../tools/testing/selftests/x86/sysret_ss_attrs_64' failed
make: *** [.../tools/testing/selftests/x86/sysret_ss_attrs_64] Error 1

Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>