net: dsa: mv88e6xxx: fix comments and macro names in mv88e6390_g1_mgmt_rsvd2cpu

The macros have an extraneous '800' (after 0180C2 there should be just
six nibbles, with X representing one), while the comments have
interchanged c2 and 80 and an extra :00.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>