ARM: use TLS register for 'current' on !SMP as well

Enable the use of the TLS register to hold the 'current' pointer also on
non-SMP configurations that target v6k or later CPUs. This will permit
the use of THREAD_INFO_IN_TASK as well as IRQ stacks and vmap'ed stacks
for such configurations.

Acked-by: Linus Walleij <[email protected]>
Acked-by: Nicolas Pitre <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>
Tested-by: Marc Zyngier <[email protected]>
Tested-by: Vladimir Murzin <[email protected]> # ARMv7M

arch/arm/Kconfig

@@ -1154,7 +1154,7 @@ config SMP_ON_UP
 
 config CURRENT_POINTER_IN_TPIDRURO
  def_bool y
- depends on SMP && CPU_32v6K && !CPU_V6
+ depends on CPU_32v6K && !CPU_V6
 
 config IRQSTACKS
  def_bool y