crypto: msm: ota: check potential integer overflow on ioctl

Integer addition and multiplication of two 16 bits integer may overflow.
Add overflow checking and prevention in the driver. The stats counters
are changed from 32 bits to 64 bits as well.

Change-Id: Icf243d8e5f375d19ce850c2b21664b74ce58612f
Acked-by: Chemin Hsieh <cheminh@qti.qualcomm.com>
Signed-off-by: Venkatesh Yadav Abbarapu <quicvenkat@codeaurora.org>