[MIPS] Cobalt 64-bits kernels can be safely unmarked experimental

64-bits Cobalt kernels run fine.
Signed-off-by: Florian Fainelli <florian.fainelli@telecomint.eu>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -72,7 +72,7 @@ config MIPS_COBALT
 	select SYS_HAS_CPU_NEVADA
 	select SYS_HAS_EARLY_PRINTK
 	select SYS_SUPPORTS_32BIT_KERNEL
-	select SYS_SUPPORTS_64BIT_KERNEL if EXPERIMENTAL
+	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_LITTLE_ENDIAN
 	select GENERIC_HARDIRQS_NO__DO_IRQ