kni: disable for 32-bit meson builds

The kni library is not supported on 32-bit so disable it for those
builds using meson.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>

lib/librte_kni/meson.build

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # Copyright(c) 2017 Intel Corporation
 
-if host_machine.system() != 'linux'
+if host_machine.system() != 'linux' or cc.sizeof('void *') == 4
 	build = false
 endif
 version = 2