refactor(drivers/marvell/comphy-3700): rename Idle Sync Enable register constants

According to the functional specification, the register at offset 0x48
is called Idle Sync Enable, not Unit Control or some such.

Rename the constants.

Only bit 12 of this register is defined, all other bits are reserved.
But for some reason the code needs the default value of the other bits,
so we also rename constant UNIT_CTRL_DEFAULT_VALUE to
IDLE_SYNC_EN_DEFAULT_VALUE.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Change-Id: Ia4f80f945a8f31c190cd9a1875d50d892e72825f
2 files changed