cmake: Add liboqs to fizz-config

Summary:
The Fizz::Fizz cmake target public interface changes depending whether or not
liboqs was found during the configure stage. If liboqs was found during configuration, then
it is included as a dependency to Fizz. Consequently, we need to ensure that
the generated fizz-config.cmake file that our downstream consumers use also
find this dependency.

Reviewed By: abakiaydin

Differential Revision: D58302705

fbshipit-source-id: 5ad42ea7a9536675c3a0866fd56091dc66f18e33

fizz/cmake/fizz-config.cmake.in

@@ -19,16 +19,22 @@
 set_and_check(FIZZ_INCLUDE_DIR "@PACKAGE_INCLUDE_INSTALL_DIR@")
 set_and_check(FIZZ_CMAKE_DIR "@PACKAGE_CMAKE_INSTALL_DIR@")
 
+set(FIZZ_HAVE_OQS "@FIZZ_HAVE_OQS@")
+
 if (NOT TARGET fizz::fizz)
   include("${FIZZ_CMAKE_DIR}/fizz-targets.cmake")
 endif()
 
 set(FIZZ_LIBRARIES fizz::fizz)
 
 include(CMakeFindDependencyMacro)
+
 find_dependency(Sodium)
 find_dependency(folly CONFIG)
 find_dependency(ZLIB)
+if(FIZZ_HAVE_OQS)
+    find_dependency(liboqs CONFIG)
+endif()
 
 if (NOT fizz_FIND_QUIETLY)
   message(STATUS "Found fizz: ${PACKAGE_PREFIX_DIR}")