Move BoringSSL.podspec into src, and point Podfiles to it
diff --git a/examples/objective-c/helloworld/Podfile b/examples/objective-c/helloworld/Podfile
index 16af075..eebf054 100644
--- a/examples/objective-c/helloworld/Podfile
+++ b/examples/objective-c/helloworld/Podfile
@@ -2,6 +2,7 @@
 platform :ios, '8.0'
 
 pod 'Protobuf', :path => "../../../third_party/protobuf"
+pod 'BoringSSL', :podspec => "../../../src/objective-c"
 pod 'gRPC', :path => "../../.."
 
 target 'HelloWorld' do