ec/google: Generalize communication protocol support in EC drivers.

Since EC protocol v3, the packet format will be the same for all buses (inclding
I2C, SPI, and LPC). That will simplify the implementation in each individual bus
driver source file.

To prepare for that, we will move the protocol part into crosec_proto.c:
crosec_command_proto, with bus driver in callback "crosec_io".

Change-Id: I9ccd19a57a182899dd1ef1cd90598679c1546295
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: http://review.coreboot.org/3749
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
3 files changed