arm: Fix Kconfig for proper display menu

Some config options should not have prompt. They are selected by choosing
target.

Signed-off-by: York Sun <york.sun@nxp.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/cpu/armv7/ls102xa/Kconfig b/arch/arm/cpu/armv7/ls102xa/Kconfig
index 920eb4a..f0e7ae9 100644
--- a/arch/arm/cpu/armv7/ls102xa/Kconfig
+++ b/arch/arm/cpu/armv7/ls102xa/Kconfig
@@ -1,6 +1,7 @@
 config ARCH_LS1021A
-	bool "Freescale Layerscape LS1021A SoC"
+	bool
 	select SYS_FSL_ERRATUM_A010315
 
 config LS1_DEEP_SLEEP
-	bool "Freescale Layerscape 1 deep sleep"
+	bool "Deep sleep"
+	depends on ARCH_LS1021A