arm64/Kconfig: Make the ARM64_PA/VA_BITS a true Kconfig variable

Enforcing the default 48-bit VA for everyone also implies a 4 page table
translation system. However, if less than 40 bits are needed, a full
translation table level can be dropped, making the translations faster.

Thus, make this into a configurable option, instead of enforcing the same
address widht for everyone.

arch/arm64/Kconfig

@@ -344,6 +344,24 @@ config ARM64_ICACHE_DISABLE
 	bool "Disable ICACHE at __start"
 	default n
 
+config ARM64_VA_BITS
+	int "Virtual address space size"
+	default 48
+	---help---
+		Allows choosing one of multiple possible virtual address
+		space sizes. The level of translation table is determined by
+		a combination of page size and virtual address space size.
+
+		The choice could be: 32, 36, 42, 48
+
+config ARM64_PA_BITS
+	int "Physical address space size"
+	default 48
+	---help---
+		Choose the maximum physical address range that the kernel will support.
+
+		The choice could be: 32, 36, 42, 48
+
 if ARCH_CHIP_A64
 source "arch/arm64/src/a64/Kconfig"
 endif

arch/arm64/src/common/arm64_arch.h

@@ -265,23 +265,6 @@
 
 #define CONFIG_MAX_XLAT_TABLES      10
 
-/* Virtual address space size
- * Allows choosing one of multiple possible virtual address
- * space sizes. The level of translation table is determined by
- * a combination of page size and virtual address space size.
- *
- * The choice could be: 32, 36, 42, 48
- */
-
-#define CONFIG_ARM64_VA_BITS        48
-/* Physical address space size
- * Choose the maximum physical address range that the kernel will support.
- *
- * The choice could be: 32, 36, 42, 48
- */
-
-#define CONFIG_ARM64_PA_BITS        48
-
 #define L1_CACHE_SHIFT              (6)
 #define L1_CACHE_BYTES              BIT(L1_CACHE_SHIFT)