Add lost install command

This was previously contained in EASTL but was lost due to
376bcdc93502208b3e61b88c911fad0f9c9e3f60.

CMakeLists.txt

@@ -30,3 +30,8 @@ add_library(EABase INTERFACE)
 # Include dirs
 #-------------------------------------------------------------------------------------------
 target_include_directories(EABase INTERFACE include/Common)
+
+#-------------------------------------------------------------------------------------------
+# Installation
+#-------------------------------------------------------------------------------------------
+install(DIRECTORY include/Common/EABase DESTINATION include)