mwifiex: reduce firmware poll retries

After downloading the firmware, firmware status is checked by
reading a register. Polling interval is 100 msecs. Therefore 100
retries means the status is checked for 10 secs which is more than
sufficient for firmware to get ready.

This patch removes 1000 retries macro usage, because 100secs
time is not practical.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>