[ARM] fix OMAP include loops

OMAP has two include loops in its header files:

  asm-arm/hardware.h <- asm-arm/arch-omap/io.h <-
   asm-arm/arch-omap/hardware.h <- asm-arm/hardware.h

  asm-arm/arch-omap/board-palmte.h <-
   asm-arm/arch-omap/hardware.h <- asm-arm/hardware.h <-
   asm-arm/arch-omap/gpio.h <- asm-arm/arch-omap/board-palmte.h

Circular include dependencies are dangerous since they can result in
inconsistent definitions being provided to other code, especially if
'#ifndef' constructs are used.

Solve these by removing the offending includes, and add additional
includes where necessary.

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>