mk: fix 32-bit link with gcc
mk: fix 32-bit link with gcc

Some linker options were not prefixed by -Wl, when using CC:
	-z muldefs
	-melf_i386 (CPU_LDFLAGS in 32-bit config)

I didn't see any error with -z muldefs but it isn't documented in gcc
manual. So it's safer to explicitly pass it to the linker.
Also building 32-bit shared library raises this error:
	gcc: error: unrecognized command line option ‘-melf_i386’

Using macro linkerprefix fixes it.

Signed-off-by: Thomas Monjalon <ee2fa8b2681c737f775687e475dcbf2028a412f1@6wind.com>
Reviewed-by: Neil Horman <3316dc2d77df57653443c0391a5296176d6ca9c3@tuxdriver.com>
Acked-by: Olivier Matz <dfcc1510895413197abb4336e39bb0a3906cba71@6wind.com>

phermansson/dpdk,phermansson/dpdk,phermansson/dpdk,phermansson/dpdk