hw/arm: Express dependencies of stellaris with Kconfig

This patch is slightly based on earlier work by Ákos Kovács (i.e.
his "hw/arm/Kconfig: Add ARM Kconfig" patch).
Tested-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: NThomas Huth <thuth@redhat.com>

default-configs/arm-softmmu.mak

@@ -16,6 +16,7 @@ CONFIG_MUSCA=y
 CONFIG_CHEETAH=y
 CONFIG_SX1=y
 CONFIG_NSERIES=y
+CONFIG_STELLARIS=y
 
 CONFIG_VGA=y
 CONFIG_NAND=y
@@ -24,16 +25,10 @@ CONFIG_SERIAL=y
 CONFIG_MAX7310=y
 CONFIG_TMP421=y
 CONFIG_PCA9552=y
-CONFIG_STELLARIS=y
-CONFIG_STELLARIS_INPUT=y
-CONFIG_STELLARIS_ENET=y
-CONFIG_SSD0303=y
-CONFIG_SSD0323=y
 CONFIG_DDC=y
 CONFIG_SII9022=y
 CONFIG_ADS7846=y
 CONFIG_MAX111X=y
-CONFIG_SSI_SD=y
 CONFIG_SSI_M25P80=y
 CONFIG_ALLWINNER_EMAC=y
 CONFIG_IMX_FEC=y

hw/arm/Kconfig

@@ -91,6 +91,17 @@ config REALVIEW
 
 config STELLARIS
     bool
+    select ARM_V7M
+    select CMSDK_APB_WATCHDOG
+    select I2C
+    select PL011 # UART
+    select PL022 # Serial port
+    select PL061 # GPIO
+    select SSD0303 # OLED display
+    select SSD0323 # OLED display
+    select SSI_SD
+    select STELLARIS_INPUT
+    select STELLARIS_ENET # ethernet
 
 config STRONGARM
     bool