refactor(drivers/marvell/comphy-3700): move and add comment for COMPHY_RESERVED_REG

The COMPHY_RESERVED_REG (offset 0x0E) is currently defined between
COMPHY_KVCO_CAL_CTRL (0x02) and COMPHY_DIG_LOOPBACK_EN (0x23).

But this register does not come from PHY lane register space. The
address 0x0E is not relative to PHY lane registers base address.

It only exists in the indirect register space, before PHY lane 2
registers (which start at address 0x200).

Move its definition in the header and add a comment.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Change-Id: Ie726384b980ace83d8ea327df09d928db74c2ab7
1 file changed