package/efl: avoid optimization flags added by meson

package/efl: avoid optimization flags added by meson

Efl's meson build system add some optimization flags related to cpu
architecture [1]. In the context of Buildroot, such optimization flags
are already provided by the toolchain wrapper.

For ppc, efl's meson expect the altivec support is available but this is
not the case for ppc e500 cpus.

Disable native-arch-optimization option to avoid such issue.

[1] https://git.enlightenment.org/core/efl.git/tree/meson.build?h=v1.24.3#n165

Fixes:
http://autobuild.buildroot.net/results/dd2586be32c25d93eebfaa743c1f7d36915bb0d7

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>