sh: Expose physical addressing mode through cpuinfo.

CPUs can be in either the legacy 29-bit or 32-bit physical addressing
modes. This follows the x86 approach of tracking the phys bits in cpuinfo
and exposing it to userspace through procfs.

This change was requested to permit kexec-tools to detect the physical
addressing mode in order to determine the appropriate address mangling.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/cpu/init.c

@@ -340,6 +340,8 @@ asmlinkage void __cpuinit cpu_init(void)
 	 */
 	current_cpu_data.asid_cache = NO_CONTEXT;
 
+	current_cpu_data.phys_bits = __in_29bit_mode() ? 29 : 32;
+
 	speculative_execution_init();
 	expmask_init();