driver: bmi160: Check enable_fifo flags before processing FIFO
driver: bmi160: Check enable_fifo flags before processing FIFO

If there is an interrupt pending after we suspend the BMI160, we will
try to collect length from the FIFO, but the FIFO is suspended.

Bring back enable_fifo flags check before processing the FIFO.
It has been move after gathering the length in CL:1128555

BUG=b:127321764,b:131272795
BRANCH=master
TEST=Using flip_flop.sh script at b/131272795#comment2
Check the messages "unexpected empty FIFO" disappear.

Change-Id: Iaab1a7f3607b902acd92b75c926365d7eb09fd5e
Signed-off-by: Gwendal Grignou <190c5a5edfcf62e0246559bf31fa7548674de3ad@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1585420
Reviewed-by: Enrico Granata <f861e98f10aee98dc7dce70e80887ecdfdeb65b1@chromium.org>
(cherry picked from commit d17cd2add14f1f1e32bd58d51d60a2c93f17f055)
Reviewed-on: https://chromium-review.googlesource.com/1585471

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec