arm, da850evm: Do pinmux configuration for EMAC together with other pinmuxes

Pinmux configuration for the EMAC was done in a separate call
of davinci_configure_pin_mux(). This patch moves all the pinmux
configuration that is done for this board to a common place.

Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Cc: Heiko Schocher <hs@denx.de>
Cc: Sandeep Paulraj <s-paulraj@ti.com>
Cc: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Acked-by: Heiko Schocher <hs@denx.de>