[POWERPC] 83xx: Fix Kconfig to only enable FP math emulation for the MPC832x

Updated MATH_EMULATION depends to be on PPC_MPC832x instead of PPC_83xx.  Only
the the MPC832x has no floating point unit in the core.  Updated the other
83xx defconfigs that got math emulation turned on incorrectly.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 0855d55..54d77a5 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -720,7 +720,7 @@
 
 config MATH_EMULATION
 	bool "Math emulation"
-	depends on 4xx || 8xx || E200 || PPC_83xx || E500
+	depends on 4xx || 8xx || E200 || PPC_MPC832x || E500
 	---help---
 	  Some PowerPC chips designed for embedded applications do not have
 	  a floating-point unit and therefore do not implement the