wil6210: enlarge FW mac_rgf_ext section for Sparrow D0

Sparrow D0 chips have slightly larger mac_rgf_ext section
in order to support extra features such as multiple virtual
interfaces.

Signed-off-by: Lior David <liord@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>