ppc4xx: Add Mnemonics for AMCC/IBM DDR2 SDRAM Controller

ppc4xx: Add Mnemonics for AMCC/IBM DDR2 SDRAM Controller

This patch completes the preprocessor mneomics for the IBM DDR2 SDRAM
controller registers (MODT and INITPLR) used by the
PowerPC405EX(r). The MMODE and MEMODE registers are unified with their
peer values used for the INITPLR MR and EMR registers,
respectively. Finally, a spelling typo is correct (MANUEL to MANUAL).

With these mnemonics in place, the CFG_SDRAM0_* magic numbers for
Kilauea are replaced by equivalent mnemonics to make it easier to
compare and contrast other 405EX(r)-based boards (e.g. during board
bring-up).

Finally, unified the SDRAM controller register dump routine such that
it can be used across all processor variants that utilize the IBM DDR2
SDRAM controller core. It produces output of the form:

	PPC4xx IBM DDR2 Register Dump:
		...
	        SDRAM_MB0CF[40] = 0x00006701
		...

which is '<mnemonic>[<DCR #>] = <value>'. The DCR number is included
since it is not uncommon that the DCR values in header files get mixed
up and it helps to validate, at a glance, they match what is printed
in the user manual.

Tested on:
  AMCC Kilauea/Haleakala:
  - NFS Linux Boot: PASSED
  - NAND Linux Boot: PASSED

Signed-off-by: Grant Erickson <gerickson@nuovations.com>
Signed-off-by: Stefan Roese <sr@denx.de>