hw/arm: Express dependencies of the fsl-imx31 machine with Kconfig

Add Kconfig dependencies for the fsl-imx31 / kzm machine.
This patch is slightly based on earlier work by Ákos Kovács (i.e.
his "hw/arm/Kconfig: Add ARM Kconfig" patch).

Reviewed-by: Peter Chubb <peter.chubb@data61.csiro.au>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

default-configs/arm-softmmu.mak

@@ -10,6 +10,7 @@ CONFIG_PCI_TESTDEV=y
 CONFIG_EXYNOS4=y
 CONFIG_HIGHBANK=y
 CONFIG_INTEGRATOR=y
+CONFIG_FSL_IMX31=y
 
 CONFIG_VGA=y
 CONFIG_NAND=y
@@ -68,7 +69,6 @@ CONFIG_TSC210X=y
 CONFIG_BLIZZARD=y
 CONFIG_ONENAND=y
 CONFIG_TUSB6010=y
-CONFIG_IMX=y
 CONFIG_MAINSTONE=y
 CONFIG_MPS2=y
 CONFIG_MUSCA=y
@@ -115,7 +115,6 @@ CONFIG_ALLWINNER_A10_PIC=y
 CONFIG_ALLWINNER_A10=y
 
 CONFIG_FSL_IMX6=y
-CONFIG_FSL_IMX31=y
 CONFIG_FSL_IMX25=y
 CONFIG_FSL_IMX7=y
 CONFIG_FSL_IMX6UL=y

hw/arm/Kconfig

@@ -98,6 +98,10 @@ config FSL_IMX25
 
 config FSL_IMX31
     bool
+    select SERIAL
+    select IMX
+    select IMX_I2C
+    select LAN9118
 
 config FSL_IMX6
     bool

hw/misc/Kconfig

@@ -76,6 +76,8 @@ config ECCMEMCTL
 config IMX
     bool
     select PTIMER
+    select SSI
+    select USB_EHCI_SYSBUS
 
 config STM32F2XX_SYSCFG
     bool