[DO-971] ffmpeg recipe with requirements (!9)

Co-authored-by: aleksandr.vodyanov <aleksandr.vodyanov@avroid.tech>
Reviewed-on: https://git.avroid.tech/Conan/conan_build/pulls/9

recipes/libwebp/all/patches/1.1.0-0002-qnx.patch

@@ -0,0 +1,14 @@
+diff --git a/cmake/deps.cmake b/cmake/deps.cmake
+index f19c0378..7b2d7cd7 100644
+--- a/cmake/deps.cmake
++++ b/cmake/deps.cmake
+@@ -24,7 +24,8 @@ check_c_source_compiles("
+ # Check for libraries.
+ find_package(Threads)
+ if(Threads_FOUND)
+-  if(CMAKE_USE_PTHREADS_INIT)
++  # work around cmake bug on QNX (https://chromium-review.googlesource.com/c/webm/libwebp/+/2637274)
++  if(CMAKE_USE_PTHREADS_INIT AND NOT CMAKE_SYSTEM_NAME STREQUAL "QNX")
+     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pthread")
+   endif()
+   foreach(PTHREAD_TEST HAVE_PTHREAD_PRIO_INHERIT PTHREAD_CREATE_UNDETACHED)