rsi: SDIO Rx packet processing enhancement

Newer firmware sends information about number of blocks through
interrupt only. We don't need to read extra register for this.
This patch adds needed driver changes for this enhancment. The
change here is backward compatible

Signed-off-by: Karun Eagalapati <karun256@gmail.com>
Signed-off-by: Amitkumar Karwar <amit.karwar@redpinesignals.com>
Signed-off-by: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>