omap3: use only fixed-size types inside ctrl_structs

replace variable types in ctrl_structs for omap3 by those with
fixed size (u8, u16, u32).
Additional ifndef-protection is needed by examples which do not
compile when including asm/types.h

Signed-off-by: Matthias Ludwig <mludwig@ultratronik.de>
Signed-off-by: Dirk Behme <dirk.behme@googlemail.com>