If CONFIG_CPU_V6 is enabled, avoid using the double-word exclusive
instructions in the kernel's atomic implementations as these are not
supported.  Fall back to the generic spinlock code instead.
Acked-by: NTony Lindgren <tony@atomide.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Tested-by: NSourav Poddar <sourav.poddar@ti.com>
Tested-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>