ARM: 5759/1: Add register information of threads to coredump

Defines ELF_CORE_COPY_TASK_REGS so that CPU register information
of every thread is included in coredump. Without this, only the faulting
thread is coredumped.

Cc: Roger Quadros <ext-roger.quadros@nokia.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>