net/i40e: disable AVX512 with MinGW
net/i40e: disable AVX512 with MinGW

Disable i40e AVX512 code path for Windows build to
avoid the MinGW build error:
	Error: invalid register for .seh_savexmm

Signed-off-by: Leyi Rong <a64575982df652f4749a148e140caaa64f8b1459@intel.com>
Tested-by: Pallavi Kadam <04c73ddce9f45f6664a05521f1a0d9e2539b2e10@intel.com>
Tested-by: David Marchand <f28529695cfa9e3e1eb84e7072aa626af4abb18e@redhat.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk