ia64: expose number of page table levels on Kconfig level

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

We need to define PGTABLE_LEVELS before sourcing init/Kconfig:
arch/Kconfig will define default value and it's sourced from init/Kconfig.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 074e52bf..4f9a666 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -1,3 +1,8 @@
+config PGTABLE_LEVELS
+	int "Page Table Levels" if !IA64_PAGE_SIZE_64KB
+	range 3 4 if !IA64_PAGE_SIZE_64KB
+	default 3
+
 source "init/Kconfig"
 
 source "kernel/Kconfig.freezer"
@@ -286,19 +291,6 @@
 
 endchoice
 
-choice
-	prompt "Page Table Levels"
-	default PGTABLE_3
-
-config PGTABLE_3
-	bool "3 Levels"
-
-config PGTABLE_4
-	depends on !IA64_PAGE_SIZE_64KB
-	bool "4 Levels"
-
-endchoice
-
 if IA64_HP_SIM
 config HZ
 	default 32