src/mainboard/*/*/board_info.txt: Added Release year for boards

To simplify browsing the "Supported hardware" list, I added Release year
for the hardware from asus, asrock, gigabyte, msi, via, tyan, intel,
lenovo, apple, jetway and hp. Still several models and manufacturers to
add information to. This is more of a proof-of-concept.
The "Release year" will be shown in the wiki page.

Change-Id: I6bc14ed06ac7c6b3c9f054b49f08cb9b3dc47947
Signed-off-by: Mathias Friman <mathias@workplays.se>
Reviewed-on: http://review.coreboot.org/9963
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Edward O'Callaghan <edward.ocallaghan@koparo.com>

src/mainboard/apple/macbook11/board_info.txt

@@ -5,4 +5,4 @@ ROM protocol: SPI
 ROM socketed: n
 Flashrom support: n
 Clone of: apple/macbook21
-
+Release year: 2006

src/mainboard/apple/macbook21/board_info.txt

@@ -4,3 +4,4 @@ ROM package: SOIC-8
 ROM protocol: SPI
 ROM socketed: n
 Flashrom support: y
+Release year: 2007