powerpc/fsl_msi: add removal path and probe failing path

Also cleanup the probe function.

Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/sysdev/fsl_msi.h b/arch/powerpc/sysdev/fsl_msi.h
index 8fc5523..624580c 100644
--- a/arch/powerpc/sysdev/fsl_msi.h
+++ b/arch/powerpc/sysdev/fsl_msi.h
@@ -32,6 +32,7 @@
 	u32 msi_addr_hi;
 	void __iomem *msi_regs;
 	u32 feature;
+	int msi_virqs[NR_MSI_REG];
 
 	struct msi_bitmap bitmap;