[flashrom] Add URLs for three boards, fix a typo and add a note

[Idwer Vollering]

Add URLs for boards ASUS K8V, ASUS K8V SE Deluxe, Elitegroup K7S5A.
FIxes a typo, adds a note for ASUS M2N-E.

Signed-off-by: Idwer Vollering