ColdFire: Modules header files cleanup

Consolidate ATA, ePORT, QSPI, FlexCan, PWM, RNG,
MDHA, SKHA, INTC, and FlexBus structures and
definitions in immap_5xxx.h to more unify modules
header files. Append DSPI support for m547x_8x.
SSI cleanup. Remove USB Host structure from immap_539.h.
Apply changes to use FlexBus structures in mcf52x2's
cpu_init.c and platform configuration files.

Signed-off-by: TsiChung Liew <Tsi-Chung.Liew@freescale.com>