[POWERPC] Abolish unused ucBoardRev variables

asm-powerpc/processor.h declares, and arch/ppc/platforms/prep_setup.c
defines variables ucBoardRev, ucBoardRevMaj and ucBoardRevMin which
are used nowhere in the current kernel (neither in arch/ppc nor
arch/powerpc).  This removes them.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

arch/ppc/platforms/prep_setup.c

@@ -69,9 +69,6 @@
 
 TODC_ALLOC();
 
-unsigned char ucBoardRev;
-unsigned char ucBoardRevMaj, ucBoardRevMin;
-
 extern unsigned char prep_nvram_read_val(int addr);
 extern void prep_nvram_write_val(int addr,
 				 unsigned char val);

include/asm-powerpc/processor.h

@@ -43,14 +43,6 @@ extern int _chrp_type;
 /* what kind of prep workstation we are */
 extern int _prep_type;
 
-/*
- * This is used to identify the board type from a given PReP board
- * vendor. Board revision is also made available. This will be moved
- * elsewhere soon
- */
-extern unsigned char ucBoardRev;
-extern unsigned char ucBoardRevMaj, ucBoardRevMin;
-
 #endif /* CONFIG_PPC_PREP */
 
 #endif /* defined(__KERNEL__) && defined(CONFIG_PPC32) */