gcc: fix undefined reference to .tdata

This fix is done in development tree:
http://github.com/foss-for-synopsys-dwc-arc-processors/gcc/commit/366cc86e4f8ff6f00f0b731dc6f78d22c7ac9e0a
and will be a part of the next release of ARC GNU tools.
Once that new release happens this patch must be removed.

Fixes:
http://autobuild.buildroot.net/results/8b22ac0dc9e3c1cd44f2fdbe5cc99a41cf77f454/
http://autobuild.buildroot.net/results/37e9c3c79e0a6aea5b89428c2226811ebb3fd611/
http://autobuild.buildroot.net/results/37e9c3c79e0a6aea5b89428c2226811ebb3fd611/
and many others.

Prerequisite:
"ARC: update tools to arc-2015.06 release": http://patchwork.ozlabs.org/patch/495837/



Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Anton Kolesov <akolesov@synopsys.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>