Add comments to bpf properties

Bug: 240141438
Test: m soong_docs
Change-Id: I86388391da9b6f30f0f3745490641e918d68c046

bpf/bpf.go

@@ -69,12 +69,23 @@ type BpfModule interface {
 }
 
 type BpfProperties struct {
-	Srcs         []string `android:"path"`
-	Cflags       []string
+	// source paths to the files.
+	Srcs []string `android:"path"`
+
+	// additional cflags that should be used to build the bpf variant of
+	// the C/C++ module.
+	Cflags []string
+
+	// directories (relative to the root of the source tree) that will
+	// be added to the include paths using -I.
 	Include_dirs []string
-	Sub_dir      string
-	// If set to true, generate BTF debug info for maps & programs
-	Btf    *bool
+
+	// optional subdirectory under which this module is installed into.
+	Sub_dir string
+
+	// if set to true, generate BTF debug info for maps & programs.
+	Btf *bool
+
 	Vendor *bool
 
 	VendorInternal bool `blueprint:"mutated"`