ARM i.MX irq: Compile avic irq code only on SoCs that need it

This patch adds a Kconfig option for the avic irq controller
and lets the SoCs that need it select this option.
Also, as we have two irq controllers for i.MX, irq.c is not
appropriate anymore, so rename it to avic.c

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/mach-imx/Kconfig

@@ -6,26 +6,30 @@ config SOC_IMX1
 	select CPU_ARM920T
 	select IMX_HAVE_DMA_V1
 	select IMX_HAVE_IOMUX_V1
+	select MXC_AVIC
 
 config SOC_IMX21
 	bool
 	select CPU_ARM926T
 	select ARCH_MXC_AUDMUX_V1
 	select IMX_HAVE_DMA_V1
 	select IMX_HAVE_IOMUX_V1
+	select MXC_AVIC
 
 config SOC_IMX25
 	bool
 	select CPU_ARM926T
 	select ARCH_MXC_AUDMUX_V2
 	select ARCH_MXC_IOMUX_V3
+	select MXC_AVIC
 
 config SOC_IMX27
 	bool
 	select CPU_ARM926T
 	select ARCH_MXC_AUDMUX_V1
 	select IMX_HAVE_DMA_V1
 	select IMX_HAVE_IOMUX_V1
+	select MXC_AVIC
 
 if ARCH_MX1
 

arch/arm/mach-mx3/Kconfig

@@ -15,13 +15,15 @@ config SOC_IMX31
 	select IMX_HAVE_PLATFORM_MXC_RNGA
 	select ARCH_MXC_AUDMUX_V2
 	select ARCH_MX31
+	select MXC_AVIC
 
 config SOC_IMX35
 	bool
 	select ARCH_MXC_IOMUX_V3
 	select ARCH_MXC_AUDMUX_V2
 	select HAVE_EPIT
 	select ARCH_MX35
+	select MXC_AVIC
 
 comment "MX3 platforms:"
 

arch/arm/plat-mxc/Kconfig

@@ -70,6 +70,9 @@ config MXC_TZIC
 	  containing this interrupt controller.
 	  Say N here only if you are really sure.
 
+config MXC_AVIC
+	bool
+
 config MXC_PWM
 	tristate "Enable PWM driver"
 	select HAVE_PWM

arch/arm/plat-mxc/Makefile

@@ -3,10 +3,11 @@
 #
 
 # Common support
-obj-y := irq.o clock.o gpio.o time.o devices.o cpu.o system.o
+obj-y := clock.o gpio.o time.o devices.o cpu.o system.o
 
-# MX51 uses the TZIC interrupt controller, older platforms use AVIC (irq.o)
+# MX51 uses the TZIC interrupt controller, older platforms use AVIC
 obj-$(CONFIG_MXC_TZIC) += tzic.o
+obj-$(CONFIG_MXC_AVIC) += avic.o
 
 obj-$(CONFIG_IMX_HAVE_IOMUX_V1) += iomux-v1.o
 obj-$(CONFIG_ARCH_MXC_IOMUX_V3) += iomux-v3.o