kernel: misc:heartbeat: heartbeat device driver implementation for 2W_v2

Implement qcom heartbeat device driver for bengal_2w_v2
Heartbeat handles the fail safe display mechanism between
SOC and Display connected over LT bridge,it communicates the
Controls of bypass and mission mode to MCU connected on SPI interface.

Change-Id: I11d4ec4e058979e845fb19f178d7ac398f76dddb
Signed-off-by: Gopalarao Marthi <quic_gmarthi@quicinc.com>