scsi: ips: fix firmware timestamps for 32-bit

do_gettimeofday() is deprecated since it will stop working in 2038 on
32-bit platforms, leading to incorrect times passed to the firmware.
On 64-bit platforms the current code appears to be fine, as the
calculation passes an 8-bit century number into the firmware that can
represent times long in the future (possibly until 25599).

Using ktime_get_real_seconds() to get a 64-bit seconds value and
time64_to_tm() to convert it into the firmware format greatly simplifies
the ips timekeeping code, makes 32-bit and 64-bit behave the same way
here, and gets us closer to removing the deprecated interfaces.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>