Update README.md

Tested on Macbook Air 5,2. 
Added processor and linux version details.

Author: larutaN

README.md

@@ -45,7 +45,7 @@ This section reports those models where mbpfan was tested successfully. It does
 - MacBook Pro 6,2 15"  (Intel i7 - Linux 3.5.0)
 - MacBook Pro 6,2 15"  (Intel i7 - Linux 3.2.0)
 - MacBook Pro 2,2 15"  (Intel Core 2 Duo - Linux 3.4.4)
-- MacBook Air 5,2 (unknown)
+- MacBook Air 5,2 13"  (Intel i5 - Linux 3.16)
 - MacBook 1,1 (Intel Core Duo - Linux 3.16)
 
 Tested iMac/Mini Models