Findassimp.cmake: add hint for lib search path for Linux

Add /usr/lib64 and /usr/lib directory hints to cmake module

libassimp.so library installs in /usr/lib for 32bit or
in /usr/lib64 for 64bit distros.

All linux distros apply custom patch to extend cmake HINTs to
systems /usr/lib and /usr/lib64
(see https://gitweb.gentoo.org/repo/gentoo.git/tree/media-libs/assimp/files/findassimp-3.3.1.patch)

Signed-off-by: Maksym Sditanov <[email protected]>

cmake-modules/Findassimp.cmake

@@ -62,6 +62,8 @@ else(WIN32)
 	  assimp_LIBRARIES
 	  NAMES assimp
 	  PATHS /usr/local/lib/
+	  PATHS /usr/lib64/
+	  PATHS /usr/lib/
 	)
 
 	if (assimp_INCLUDE_DIRS AND assimp_LIBRARIES)
@@ -78,4 +80,4 @@ else(WIN32)
 	  endif (assimp_FIND_REQUIRED)
 	endif (assimp_FOUND)
 	
-endif(WIN32)
+endif(WIN32)