libgcc-common.inc: Fix broken symlinks for multilib SDK

libgcc-common.inc: Fix broken symlinks for multilib SDK

This patch fixes broken "32" symlinks for multilib settings:

MACHINE = "qemuarm64"
require conf/multilib.conf
MULTILIBS = "multilib:lib32"
DEFAULTTUNE_virtclass-multilib-lib32 = "armv7a"

and

MACHINE = "qemux86-64"
require conf/multilib.conf
MULTILIBS = "multilib:libx32"
DEFAULTTUNE_virtclass-multilib-libx32 = "x86-64-x32"

[YOCTO#8642]
[YOCTO#10380]

(From OE-Core rev: 2810671a0f96776c135137f27a5ca52194ddd692)

Signed-off-by: Juro Bystricky <juro.bystricky@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>