rsi: fill rx_params only once.

rx_params are getting updated two times in driver, which is not required.
Hence, removing duplicate updation of rx_params from rsi_prepare_skb().

Signed-off-by: Amol Hanwate <amol.hanwate@redpinesignals.com>
Signed-off-by: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>