arm, davinci: Move pinmux functions from board to arch tree

arm, davinci: Move pinmux functions from board to arch tree

Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Cc: Sandeep Paulraj <s-paulraj@ti.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Cc: Syed Mohammed Khasim <sm.khasim@gmail.com>
Cc: Sughosh Ganu <urwithsughosh@gmail.com>
Cc: Nick Thompson <nick.thompson@ge.com>
Cc: Stefano Babic <sbabic@denx.de>
Acked-by: Heiko Schocher <hs@denx.de>
Acked-by: Nick Thompson <nick.thompson@ge.com>