Revert "package/gcc: fix libgcc build for xtensa"

Revert "package/gcc: fix libgcc build for xtensa"

This reverts commit c44cf2cc97df1729577263d2b0cb5263e8cdc4c1.
Now that xtensa gas don't move literals into .init and .fini this fix is
no longer needed.

See upstream commit
https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=4111950f363221c4641dc2f33bea61cc94f34906,
which was backported to all supported binutils version, under the name
*-xtensa-fix-.init-.fini-literals-moving.patch.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
[Thomas: add more details in the commit log, as suggested by Yann
E. Morin, and using information provided by Max.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>