driver: input: sensors: SMI130 early buffer implemented

This patch allows to buffer SMI130 accel and gyro samples from driver
up to time till user space services are up and running
(or upto nth second). Buffered samples can be retrived at any time via
input subsystem by writing to below sysfs entry.
echo 1 > /sys/class/input/input*/read_acc_boot_sample
echo 1 > /sys/class/input/input*/read_gyro_boot_sample
Use config option to enable buffering feature.

Change-Id: I25109fa17bb0bea900b07c70adcb46fad34cd5c6
Signed-off-by: Puneet Yatnal <puneet@codeaurora.org>