arch: add existing archs to archs.yml for HWMv2 support

Existing Zephyr architectures are already self-contained and thereby
HWMv2 compliant.

Add all existing architectures to archs.yml.

Signed-off-by: Torsten Rasmussen <Torsten.Rasmussen@nordicsemi.no>

arch/archs.yml

@@ -1,4 +1,21 @@
 archs:
-  - name: empty
-    folder: empty
-    comment: initial file, no arch v2 defined.
+  - name: arc
+    path: arc
+  - name: arm
+    path: arm
+  - name: arm64
+    path: arm64
+  - name: mips
+    path: mips
+  - name: nios2
+    path: nios2
+  - name: posix
+    path: posix
+  - name: riscv
+    path: riscv
+  - name: sparc
+    path: sparc
+  - name: xtensa
+    path: xtensa
+  - name: x86
+    path: x86