scsi: smartpqi: fix time handling

When we have turned off RTC support, the smartpqi driver fails to build:

ERROR: "rtc_time64_to_tm" [drivers/scsi/smartpqi/smartpqi.ko] undefined!

This is easily avoided by using the generic 'struct tm' based helper rather
than the RTC specific one. While fixing this, I noticed that even though
the driver uses time64_t for storing seconds, it gets them from the
old 32-bit struct timeval. To address this, we can simplify the code
by calling ktime_get_real_seconds() directly.

Fixes: 6c223761

 ("smartpqi: initial commit of Microsemi smartpqi driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>