greybus: arche-platform: Rename spinlock variable lock => wake_detect_lock

With addition of exported function, required for TIMESYNC operation,
we need more locking mechanism for driver state, so to avoid confusion
rename existing spinlock variable to its appropriate name.

Testing Done: Tested on DB3.5 platform.

Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>