m68k: select CONFIG_GENERIC_ATOMIC64 for all m68k CPU types

There is no specific atomic64 support code for any m68k CPUs, so we should
select CONFIG_GENERIC_ATOMC64 for all. Remove the existing per CPU selection
of this and select it for all m68k.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Fengguang Wu <fengguang.wu@intel.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 4a46990..b22df94 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -5,6 +5,7 @@
 	select HAVE_AOUT if MMU
 	select HAVE_GENERIC_HARDIRQS
 	select GENERIC_IRQ_SHOW
+	select GENERIC_ATOMIC64
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG if RMW_INSNS
 	select GENERIC_CPU_DEVICES
 	select GENERIC_STRNCPY_FROM_USER if MMU