kernel: Create and export kernel headers

Create a header library which export kernel headers.
These headers are needed by modules and userspace libraries.

Change-Id: I0908e2e02ba1edfb569c5abcd0d5e1df72a40324
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>

Android.bp

@@ -0,0 +1,47 @@
+cc_binary_host {
+    name: "unifdef",
+    srcs: ["scripts/unifdef.c"],
+    sanitize: {
+        never: true,
+    },
+}
+
+gensrcs {
+    name: "gen-headers_install.sh",
+    srcs: ["scripts/headers_install.sh"],
+    tools: ["unifdef"],
+    cmd: "sed 's+scripts/unifdef+$(location unifdef)+g' $(in) > $(out)",
+    output_extension: "sh",
+}
+
+cc_prebuilt_binary {
+    name: "headers_install.sh",
+    device_supported: false,
+    host_supported: true,
+    srcs: [":gen-headers_install.sh"],
+}
+
+gensrcs {
+    name: "qcom-kernel-includes",
+    cmd: "$(location headers_install.sh) $(in) $(out)",
+    tools: ["headers_install.sh"],
+    export_include_dirs: ["include/uapi"],
+    srcs: [
+        "include/uapi/**/*.h",
+    ],
+    output_extension: "h",
+}
+
+cc_library_headers {
+    name: "qseecom-kernel-headers",
+    generated_headers: ["qcom-kernel-includes"],
+    export_generated_headers: ["qcom-kernel-includes"],
+}
+
+cc_library_headers {
+    name: "qcom_kernel_headers",
+    generated_headers: ["qcom-kernel-includes"],
+    export_generated_headers: ["qcom-kernel-includes"],
+    vendor: true,
+    recovery_available: true,
+}