input: ft5x06: Add support for firmware upgrade

Add sysfs entries to upgrade firmware from userspace.
Firmware upgrade is triggered when the device's firmware
version mismatches with userspace's firmware file.
Force firmware upgrade sysfs entry is added to force
the firmware upgrade even when the firmware versions
match.

Change-Id: I48189abe60b4bd9d54a1bbc4657707213d8eb166
Signed-off-by: Mohan Pallaka <mpallaka@codeaurora.org>
Signed-off-by: Shantanu Jain <shjain@codeaurora.org>