fix(drivers/marvell/comphy-3700): handle failures in power functions

Subroutines in power functions may fail. So propagate failures from
subroutines back to the caller of power function with appropriate error
code in return value.

Function polling_with_timeout() returns last value from polled register
on failure and zero on success. So return -ETIMEDOUT on error from power
functions like it is doing Marvell comphy-cp110 driver.

Signed-off-by: Pali Rohár <pali@kernel.org>
Change-Id: I6c709c0c9616ab26829616a42a85b713f314b201
1 file changed