powerpc/qe: Limit QE support to ppc32

Only 32-bit SoCs have a QUICC Engine so limit the config option to PPC32.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/platforms/Kconfig

@@ -266,7 +266,7 @@ config TAU_AVERAGE
 
 config QUICC_ENGINE
 	bool "Freescale QUICC Engine (QE) Support"
-	depends on FSL_SOC
+	depends on FSL_SOC && PPC32
 	select PPC_LIB_RHEAP
 	select CRC32
 	help