wil6210: make sure Rx ring sizes are correlated

When enlarging rx_ring_order module param, wil6210 fails to load
because there are not enough Rx buffers.
Fix this by enlarging number of Rx buffers at startup, if needed based
on rx_ring_order.

Change-Id: Ib74575cdd25d1ff41c40a2c170c9f89b5858db74
Signed-off-by: Dedy Lansky <dlansky@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Git-commit: 61e5ec044748486f06dec760a19dce78247b3ad8
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git


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