[Update] Update detector from synap1680 to synaptics

This update is in order to make the synaptics SL-series NPU detector more general.

- Fix detector `os` module not import bug
- Update detector type `synap1680` to `synaptics`
- Update document description `SL1680` to `Synaptics` only
- Update docker build content `synap1680` to `synaptics`

docker/synap1680/synap1680.mk

@@ -1,15 +0,0 @@
-BOARDS += synap1680
-
-local-synap1680: version
-	docker buildx bake --file=docker/synap1680/synap1680.hcl synap1680 \
-		--set synap1680.tags=frigate:latest-synap1680 \
-		--load
-
-build-synap1680: version
-	docker buildx bake --file=docker/synap1680/synap1680.hcl synap1680 \
-		--set synap1680.tags=$(IMAGE_REPO):${GITHUB_REF_NAME}-$(COMMIT_HASH)-synap1680
-
-push-synap1680: build-synap1680
-	docker buildx bake --file=docker/synap1680/synap1680.hcl synap1680 \
-		--set synap1680.tags=$(IMAGE_REPO):${GITHUB_REF_NAME}-$(COMMIT_HASH)-synap1680 \
-		--push

docker/synaptics/synaptics.hcl

@@ -16,8 +16,8 @@ target rootfs {
   target = "rootfs"
 }
 
-target synap1680 {
-  dockerfile = "docker/synap1680/Dockerfile"
+target synaptics {
+  dockerfile = "docker/synaptics/Dockerfile"
   contexts = {
     wheels = "target:wheels",
     deps = "target:deps",

docker/synaptics/synaptics.mk

@@ -0,0 +1,15 @@
+BOARDS += synaptics
+
+local-synaptics: version
+	docker buildx bake --file=docker/synaptics/synaptics.hcl synaptics \
+		--set synaptics.tags=frigate:latest-synaptics \
+		--load
+
+build-synaptics: version
+	docker buildx bake --file=docker/synaptics/synaptics.hcl synaptics \
+		--set synaptics.tags=$(IMAGE_REPO):${GITHUB_REF_NAME}-$(COMMIT_HASH)-synaptics
+
+push-synaptics: build-synaptics
+	docker buildx bake --file=docker/synaptics/synaptics.hcl synaptics \
+		--set synaptics.tags=$(IMAGE_REPO):${GITHUB_REF_NAME}-$(COMMIT_HASH)-synaptics \
+		--push