Hi Renjith,
Your implementation is correct. But you dont have to refer it any where in your code. You just need to have a "favicon.ico" (In IIS. dont know about other webservers) at the root level/folder of your website. Just Make sure you follow the below mentioned image formats to get FavIcons on Supported Mobile Devices (Blackberry, Nokia E75, SonyEricsson M600i and other high end phones).
For FavIcon, the image need to be like (this is how i rendered the Fav icon for both Desktop and Mobile phone browsers)
1) 16x16 size. 16 colours (4 Bit) or 256 colours (8 Bit)
AND
2) 32x32 size. 16 colours (4 Bit) or 256 colours (8 Bit)
<link rel="Fav Icon" href="/favicon.ico" type="image/vnd.microsoft.icon">
<link rel="icon" type="image/gif" href="http://www.yoursite.com/favicon.gif" />
Both the above tags should work in mobile as well as in Desktop Browsers. Just follow the Image size and resolutions.