ARM: v7m: add trivial suspend support

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

arch/arm/Kconfig

@@ -2270,7 +2270,7 @@ source "kernel/power/Kconfig"
 config ARCH_SUSPEND_POSSIBLE
 	depends on !ARCH_S5PC100
 	depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
-		CPU_V6 || CPU_V6K || CPU_V7 || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
+		CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
 	def_bool y
 
 config ARM_CPU_SUSPEND