IB/qib: Eliminate 64-bit jiffies use

The qib driver makes use of the the 64-bit jiffies API.

Code inspection reveals that that version of the API is not really
required.  This patch converts to use the "normal" jiffies.

Reviewed-by: Ram Vepa <ram.vepa@qlogic.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>