Move kvm-bindings crate to own directory

In preparation for creating a common workspace for kvm-bindings and
kvm-ioctls, move the kvm-bindings crate to its own directory.

A workspace Cargo.toml is not added yet because it makes git detect it
as a modification and treat kvm-bindings/Cargo.toml as a new file
instead of a rename.

Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>

Author: epilys

.buildkite/custom-tests.json

@@ -2,7 +2,7 @@
     "tests": [
         {
             "test_name": "build-fam-gnu",
-            "command": "cargo build --release --features=fam-wrappers",
+            "command": "cd kvm-bindings && cargo build --release --features=fam-wrappers",
             "platform": [
                 "x86_64",
                 "aarch64",
@@ -11,15 +11,15 @@
         },
         {
             "test_name": "build-fam-musl",
-            "command": "cargo build --release --features=fam-wrappers --target {target_platform}-unknown-linux-musl",
+            "command": "cd kvm-bindings && cargo build --release --features=fam-wrappers --target {target_platform}-unknown-linux-musl",
             "platform": [
                 "x86_64",
                 "aarch64"
             ]
         },
         {
             "test_name": "build-serde-gnu",
-            "command": "cargo build --release --features=serde",
+            "command": "cd kvm-bindings && cargo build --release --features=serde",
             "platform": [
                 "x86_64",
                 "aarch64",
@@ -28,7 +28,7 @@
         },
         {
             "test_name": "build-serde-musl",
-            "command": "cargo build --release --features=serde --target {target_platform}-unknown-linux-musl",
+            "command": "cd kvm-bindings && cargo build --release --features=serde --target {target_platform}-unknown-linux-musl",
             "platform": [
                 "x86_64",
                 "aarch64"