arm: kirkwood: iConnect : Add Ethernet support

- Currently, CONFIG_RESET_PHY_R symbol is used in
arch/arm/mach-kirkwood/include/mach/config.h for all Kirkwood
boards with mv8831116 PHY, with each board defines the function
reset_phy(). Undefine it for this board.
- Add board_eth_init(), CONFIG_DM_ETH, and CONFIG_PHY_MARVELL
to bring up Ethernet.
- Miscellaneous changes: Move constants to .c file and remove header file
board/iomega/iconnect/iconnect.h. Add CONFIG_HUSH_PARSER, use BIT macro,
and cleanup comments.

Signed-off-by: Tony Dinh <mibodhi@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>