mpc83xx: use "A" nomenclature only on mpc834x and mpc836x families

marketing didn't extend their postpend-with-an-A naming strategy
on rev.2's and higher beyond the first two 83xx families.  This
patch stops us from misreporting we're running e.g., on an MPC8313EA,
when such a name doesn't exist.

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>

arch/powerpc/cpu/mpc83xx/cpu.c

@@ -106,7 +106,9 @@ int checkcpu(void)
 			puts(cpu_type_list[i].name);
 			if (IS_E_PROCESSOR(spridr))
 				puts("E");
-			if (REVID_MAJOR(spridr) >= 2)
+			if ((SPR_FAMILY(spridr) == SPR_834X_FAMILY ||
+			     SPR_FAMILY(spridr) == SPR_836X_FAMILY) &&
+			    REVID_MAJOR(spridr) >= 2)
 				puts("A");
 			printf(", Rev: %d.%d", REVID_MAJOR(spridr),
 			       REVID_MINOR(spridr));