ARM: 6517/1: kexec: Add missing memory clobber to inline asm in crash_setup_regs()

Currently, the inline asm is passed &newregs->ARM_r0 as in input,
when modifying multiple fields of newregs.

It's plausible to assume that GCC will assume newregs->ARM_r0 is
modified when passed the address, but unfortunately this assumption
is incorrect.

Also, GCC has no way to guess that the other ARM_r* fields are
modified without the addition of a "memory" clobber.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>