preserve_crunch_context() calls __copy_to_user() which expects the
destination address to be in __user space.  setup_sigframe() properly
passes the destination address.

restore_crunch_context() calls __copy_from_user() which expects the
source address to be in __user space.  restore_sigframe() properly
passes the source address.

This fixes {preserve/restore}_crunch_context() to accept the
address as __user space and resolves the following sparse warnings:

  arch/arm/kernel/signal.c:146:31:
     warning: incorrect type in argument 1 (different address spaces)
        expected void [noderef] <asn:1>*to
        got struct crunch_sigframe *frame

  arch/arm/kernel/signal.c:156:38:
     warning: incorrect type in argument 2 (different address spaces)
        expected void const [noderef] <asn:1>*from
        got struct crunch_sigframe *frame

  arch/arm/kernel/signal.c:250:48:
     warning: incorrect type in argument 1 (different address spaces)
        expected struct crunch_sigframe *frame
        got struct crunch_sigframe [noderef] <asn:1>*<noident>

  arch/arm/kernel/signal.c:365:49:
     warning: incorrect type in argument 1 (different address spaces)
        expected struct crunch_sigframe *frame
        got struct crunch_sigframe [noderef] <asn:1>*<noident>
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>