BUGFIX: arm: data abort in get_bad_stack_swi

BUGFIX: arm: data abort in get_bad_stack_swi

When swi instruction is executed, it is expected to get message
"software interrupt" in console and dump registers and reboot, as
do_software_interrupt() in arch/arm/lib/interrupts.c.
But, actually it causes data abort accessing wrong address in get_bad_stack_swi
macro in arch/arm/cpu/v7/start.S.
This patch fixes this problem.

The same mistake in arch/arm/cpu/{arm1136,arm1176,pxa}/start.S.

Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>