microblaze/irqchip: Move intc driver to irqchip

The Xilinx AXI Interrupt Controller IP block is used by the MIPS
based xilfpga platform and a few PowerPC based platforms.

Move the interrupt controller code out of arch/microblaze so that
it can be used by everyone

Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 86f6572..85885a50 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -27,6 +27,7 @@
 	select HAVE_MEMBLOCK_NODE_MAP
 	select HAVE_OPROFILE
 	select IRQ_DOMAIN
+	select XILINX_INTC
 	select MODULES_USE_ELF_RELA
 	select OF
 	select OF_EARLY_FLATTREE