This is a basic question among webmasters according to us geographic location of the site does not affects SEO. But the IP address will be notified by search engines to differentiate the website, which belongs to particular country.
You can also achieve by setting up particular country for your domain in Google webmaster tools. If you are using CCTLD (Country code top-level domain) Google Webmaster tools automatically identifies the country.
Matt Cutts clearly explains in Google Webmaster help video that web server IP is notified for every website and it is considered to differentiate the website from particular country.
So we consider, geographic location of the site does not affects SEO. But if you are looking to target your website for particular country you can change it in Google Webmaster tools.
