arm, hawkboard: Use the pinmux configurations defined in the arch tree

arm, hawkboard: Use the pinmux configurations defined in the arch tree

The boards in board/davinci/da8xxevm/ define pinmux_config[] vectors
that contain pinmux configurations for emac, uarts, memory controllers...
In an earlier patch such pinmux configurations were added to the arch
tree. This patch makes the hawkboard use these definitions instead of
defining its own.

Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Cc: Sandeep Paulraj <s-paulraj@ti.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Syed Mohammed Khasim <sm.khasim@gmail.com>
Cc: Sughosh Ganu <urwithsughosh@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Acked-by: Heiko Schocher <hs@denx.de>