feat: Kconfig: moving the arm64 specified configs to sub-menu

Just for better readability.

Signed-off-by: Shell <smokewood@qq.com>

libcpu/Kconfig

@@ -1,29 +1,5 @@
 if ARCH_ARMV8 && ARCH_CPU_64BIT
-    menu "AArch64 Architecture Configuration"
-    config ARCH_TEXT_OFFSET
-        hex "Text offset"
-        default 0x200000
-    config ARCH_RAM_OFFSET
-        hex "RAM offset"
-        default 0
-    config ARCH_SECONDARY_CPU_STACK_SIZE
-        int "Secondary CPU stack size"
-        default 4096
-    config ARCH_HAVE_EFFICIENT_UNALIGNED_ACCESS
-        bool
-        default y
-    config ARCH_USING_GENERIC_CPUID
-        bool "Using generic cpuid implemenation"
-        select ARCH_USING_HW_THREAD_SELF
-        default y if RT_USING_OFW
-        default n
-    config ARCH_HEAP_SIZE
-        hex "Size of system heap"
-        default 0x4000000
-    config ARCH_INIT_PAGE_SIZE
-        hex "Size of init page region"
-        default 0x200000
-    endmenu
+    orsource "./aarch64/Kconfig"
 endif
 
 config ARCH_CPU_64BIT

libcpu/aarch64/Kconfig

@@ -0,0 +1,25 @@
+menu "AArch64 Architecture Configuration"
+    config ARCH_TEXT_OFFSET
+        hex "Text offset"
+        default 0x200000
+    config ARCH_RAM_OFFSET
+        hex "RAM offset"
+        default 0
+    config ARCH_SECONDARY_CPU_STACK_SIZE
+        int "Secondary CPU stack size"
+        default 4096
+    config ARCH_HAVE_EFFICIENT_UNALIGNED_ACCESS
+        bool
+        default y
+    config ARCH_USING_GENERIC_CPUID
+        bool "Using generic cpuid implemenation"
+        select ARCH_USING_HW_THREAD_SELF
+        default y if RT_USING_OFW
+        default n
+    config ARCH_HEAP_SIZE
+        hex "Size of system heap"
+        default 0x4000000
+    config ARCH_INIT_PAGE_SIZE
+        hex "Size of init page region"
+        default 0x200000
+endmenu