converters/lua-iconv: fix build on armv7

[pkubaj]

Summary

armv7 requires -fPIC too.

PR: 239623

[linimon]

Approved. IMHO there should also be an entry for armv6.

[andrew_tao173.riddles.org.uk]

Why isn't this just CFLAGS+=-fPIC ?

[pkubaj]

In D21402#467690, @andrew_tao173.riddles.org.uk wrote:

Why isn't this just CFLAGS+=-fPIC ?

Because e.g. powerpc64 doesn't need it.

[andrew_tao173.riddles.org.uk]

In D21402#467883, @pkubaj wrote:

In D21402#467690, @andrew_tao173.riddles.org.uk wrote:

Why isn't this just CFLAGS+=-fPIC ?

Because e.g. powerpc64 doesn't need it.

What that says to me is that we need a standard ${CFLAGS_PIC} variable or some such, which is defined to -fPIC on most platforms and empty on powerpc64, rather than pollute every port makefile with an ever-changing list of which arches need -fPIC and which don't.