Convert CONFIG_88F5182 et al to Kconfig

This converts the following to Kconfig:
   CONFIG_88F5182
   CONFIG_BOARD_IS_OPENRD_BASE
   CONFIG_BOARD_IS_OPENRD_CLIENT
   CONFIG_BOARD_IS_OPENRD_ULTIMATE
   CONFIG_D2NET_V2
   CONFIG_FEROCEON
   CONFIG_FEROCEON_88FR131
   CONFIG_INETSPACE_V2
   CONFIG_KW88F6192
   CONFIG_KW88F6281
   CONFIG_KW88F6702
   CONFIG_NET2BIG_V2
   CONFIG_NETSPACE_LITE_V2
   CONFIG_NETSPACE_MAX_V2
   CONFIG_NETSPACE_MINI_V2
   CONFIG_NETSPACE_V2
   CONFIG_SHEEVA_88SV131

At this point mv-plug-common.h is now only an include of mv-common.h so
remove that indirection.

Signed-off-by: Tom Rini <trini@konsulko.com>