fix(drivers/marvell/comphy-3700): drop MODE_REFDIV constant

The MODE_REFDIV constant is only used as mask of the MODE_REFDIV
register, but we already have MODE_REFDIV_MASK constant for that.

Drop MODE_REFDIV.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Change-Id: Icabb32189a7ca1a857dcf86cf0846bd0335f75d0
2 files changed