add support for custom xcode actions for bgfx.lua

Since I am working on a custom genie action called "xcode7", this serve my purpose

scripts/bgfx.lua

@@ -129,7 +129,7 @@ function bgfxProject(_name, _kind, _defines)
 				path.join(BGFX_DIR, "src/vertexdecl.cpp"),
 			}
 
-			configuration { "xcode4 or osx or ios*" }
+			configuration { "xcode* or osx or ios*" }
 				files {
 					path.join(BGFX_DIR, "src/amalgamated.mm"),
 				}
@@ -144,7 +144,7 @@ function bgfxProject(_name, _kind, _defines)
 			configuration {}
 
 		else
-			configuration { "xcode4 or osx or ios*" }
+			configuration { "xcode* or osx or ios*" }
 				files {
 					path.join(BGFX_DIR, "src/glcontext_eagl.mm"),
 					path.join(BGFX_DIR, "src/glcontext_nsgl.mm"),