arm64: Convert bool ARM64_x_LEVELS to int ARM64_PGTABLE_LEVELS

Rather than having several Kconfig options, define int
ARM64_PGTABLE_LEVELS which will be also useful in converting some of the
pgtable macros.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Jungseok Lee <jungseoklee85@gmail.com>
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index cf07cc7..8cdb7f36 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -207,14 +207,11 @@
 	default 42 if ARM64_VA_BITS_42
 	default 48 if ARM64_VA_BITS_48
 
-config ARM64_2_LEVELS
-	def_bool y if ARM64_64K_PAGES && ARM64_VA_BITS_42
-
-config ARM64_3_LEVELS
-	def_bool y if ARM64_4K_PAGES && ARM64_VA_BITS_39
-
-config ARM64_4_LEVELS
-	def_bool y if ARM64_4K_PAGES && ARM64_VA_BITS_48
+config ARM64_PGTABLE_LEVELS
+	int
+	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
+	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
+	default 4 if ARM64_4K_PAGES && ARM64_VA_BITS_48
 
 config CPU_BIG_ENDIAN
        bool "Build big-endian kernel"