arm, davinci, da850: add uart1 tx rx pinmux config

Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Tom Rini <trini@ti.com>
Cc: Sandeep Paulraj <s-paulraj@ti.com>
Cc: Tom Rini <tom.rini@gmail.com>
Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Cc: Christian Riesch <christian.riesch@omicron.at>