Fix support ARC processors without barrel-shifter

Fix support ARC processors without barrel-shifter

crt0.S for ARC used to use instruction "asr.f lp_count, r3, 2" for all cores
except ARC601. However instructions which shift more than 1 bit are
optional, so this crt0.S didn't worked for all ARC cores.

Luckily this is a shift just by 2 bits on all occassions, so fix is trivial
- use two single-bit shifts.

libgloss/ChangeLog

2016-04-29  Anton Kolesov  <anton.kolesov@synopsys.com>

        * arc/crt0.S: Fix support for processors without barrel-shifter.

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>