ARM: v6k: use CPU domain feature if we include support for arch < ARMv6K

Rather than turning off CPU domain switching when the build architecture
includes ARMv6K, thereby causing problems for ARMv6-supporting kernels,
turn it on when it's required to support a CPU architecture.
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/Kconfig

@@ -435,25 +435,30 @@ config CPU_32v3
 	bool
 	select TLS_REG_EMUL if SMP || !MMU
 	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
+	select CPU_USE_DOMAINS if MMU
 
 config CPU_32v4
 	bool
 	select TLS_REG_EMUL if SMP || !MMU
 	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
+	select CPU_USE_DOMAINS if MMU
 
 config CPU_32v4T
 	bool
 	select TLS_REG_EMUL if SMP || !MMU
 	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
+	select CPU_USE_DOMAINS if MMU
 
 config CPU_32v5
 	bool
 	select TLS_REG_EMUL if SMP || !MMU
 	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
+	select CPU_USE_DOMAINS if MMU
 
 config CPU_32v6
 	bool
 	select TLS_REG_EMUL if !CPU_32v6K && !MMU
+	select CPU_USE_DOMAINS if CPU_V6 && MMU
 
 config CPU_32v6K
 	bool "Support ARM V6K processor extensions" if !SMP
@@ -620,8 +625,6 @@ config CPU_CP15_MPU
 
 config CPU_USE_DOMAINS
 	bool
-	depends on MMU
-	default y if !CPU_32v6K
 	help
 	  This option enables or disables the use of domain switching
 	  via the set_fs() function.