motion_sense: Fix invalid optimization
motion_sense: Fix invalid optimization

We need to call irq_handler and load_fifo even if the
first sensor is disable. Nothing is done on otherwise.

Move code to recalculate sample rate to the right place.

BRANCH=smaug
TEST=Check data is collected when accel is disabled.
BUG=chrome-os-partner:39900

Change-Id: Ia6025a670abaf2e71ccbe784bce24e08becf399e
Signed-off-by: Gwendal Grignou <190c5a5edfcf62e0246559bf31fa7548674de3ad@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/289838
Reviewed-by: Vincent Palatin <70a9964ec8fd10b0b08fcc8623c2add25ddf99ac@chromium.org>

coreboot/chrome-ec,fourier49/BZ_DEV_EC,coreboot/chrome-ec,fourier49/BZ_DEV_EC,akappy7/ChromeOS_EC_LED_Diagnostics,akappy7/ChromeOS_EC_LED_Diagnostics,akappy7/ChromeOS_EC_LED_Diagnostics,fourier49/BZ_DEV_EC,akappy7/ChromeOS_EC_LED_Diagnostics,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,fourier49/BZ_DEV_EC,akappy7/ChromeOS_EC_LED_Diagnostics