QuEST: Build error Power9 RHEL

$ uname -a
Linux power9-vm8.xxxxxx.xxx 4.14.0-115.10.1.el7a.ppc64le #1 SMP Wed Jun 26 09:32:17 UTC 2019 ppc64le ppc64le ppc64le GNU/Linux
$ cat /etc/os-release 
NAME="Red Hat Enterprise Linux Server"
VERSION="7.6 (Maipo)"
ID="rhel"
ID_LIKE="fedora"
VARIANT="Server"
VARIANT_ID="server"
VERSION_ID="7.6"
PRETTY_NAME="Red Hat Enterprise Linux"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:redhat:enterprise_linux:7.6:GA:server"
HOME_URL="https://www.redhat.com/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"

REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 7"
REDHAT_BUGZILLA_PRODUCT_VERSION=7.6
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="7.6"
$ cmake ..
-- The C compiler identification is GNU 9.2.0
-- The CXX compiler identification is GNU 9.2.0
-- Check for working C compiler: /usr/local/gcc-9.2.0/bin/gcc
-- Check for working C compiler: /usr/local/gcc-9.2.0/bin/gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/local/gcc-9.2.0/bin/g++
-- Check for working CXX compiler: /usr/local/gcc-9.2.0/bin/g++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- GPU acceleration is OFF
-- OMP acceleration is ON
-- MPI distribution is OFF
-- Found OpenMP_C: -fopenmp (found version "4.5") 
-- Found OpenMP_CXX: -fopenmp (found version "4.5") 
-- Found OpenMP: TRUE (found version "4.5")  
-- Compiling examples/tutorial_example.c to executable demo
-- Found PythonInterp: /usr/bin/python3.6 (found version "3.6.8") 
-- Testing is ON
-- Configuring done
-- Generating done
-- Build files have been written to: /home/jwoehr/work/Qiskit/QuEST/build
$ make
Scanning dependencies of target QuEST
[ 10%] Building C object QuEST/CMakeFiles/QuEST.dir/src/QuEST.c.o
gcc: error: unrecognized command line option ‘-mavx’
make[2]: *** [QuEST/CMakeFiles/QuEST.dir/src/QuEST.c.o] Error 1
make[1]: *** [QuEST/CMakeFiles/QuEST.dir/all] Error 2
make: *** [all] Error 2