Its necessary to establish an initial state on the wake-detect lines before
enabling timesync on APB/GPB in order to ensure all GPIO edge-transitions are
correctly interpreted by the receiving processor.
This patch adds the operations defined in the Greybus specification to
greybus_protocols.h, this involves adding the
SVC_TIMESYNC_WAKE_PINS_ACQUIRE and SVC_TIMESYNC_WAKE_PINS_RELEASE commands
and moving the 'strobe_mask' parameter from 'struct
gb_svc_timesync_enable_request' to 'struct
gb_svc_timesync_wd_pins_acquire_request' since the communication of the
strobe_mask will be communicated before preparing any of the bridges to
receive the TimeSync pulses.
A separate patch to the greybus specification describes the transition
between the wake sub-state and the timesync sub-state.