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/esd/voh405/voh405.c b/board/esd/voh405/voh405.c
index 9127550..7477f56 100644
--- a/board/esd/voh405/voh405.c
+++ b/board/esd/voh405/voh405.c
@@ -99,7 +99,7 @@
 	/*
 	 * 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;
 }