ppc4xx: Big cleanup of PPC4xx defines

This patch cleans up multiple issues of the 4xx register (mostly
DCR, SDR, CPR, etc) definitions:

- Change lower case defines to upper case (plb4_acr -> PLB4_ACR)
- Change the defines to better match the names from the
  user's manuals (e.g. cprpllc -> CPR0_PLLC)
- Removal of some unused defines

Please test this patch intensive on your PPC4xx platform. Even though
I tried not to break anything and tested successfully on multiple
4xx AMCC platforms, testing on custom platforms is recommended.

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/board/gdsys/neo/neo.c b/board/gdsys/neo/neo.c
index 817ce17..628ce3d 100644
--- a/board/gdsys/neo/neo.c
+++ b/board/gdsys/neo/neo.c
@@ -43,7 +43,7 @@
 	 * EBC Configuration Register: set ready timeout to 512 ebc-clks
 	 * -> ca. 15 us
 	 */
-	mtebc(epcr, 0xa8400000);	/* ebc always driven */
+	mtebc(EBC0_CFG, 0xa8400000);	/* ebc always driven */
 
 	return 0;
 }