microblaze/irq: prepare for drivers/irqchip/irqchip.h removal

The IRQCHIP_DECLARE macro migrated to 'include/linux/irqchip.h'.

See commit 91e20b50
("irqchip: Move IRQCHIP_DECLARE macro to include/linux/irqchip.h").

This patch removes the inclusion of private header 'drivers/irqchip/irqchip.h'
and replaces it with the inclusion of 'include/linux/irqchip.h'.

Signed-off-by: Joel Porquet <joel@porquet.org>
Cc: vgupta@synopsys.com
Cc: monstr@monstr.eu
Cc: ralf@linux-mips.org
Cc: jason@lakedaemon.net
Link: http://lkml.kernel.org/r/12384045.pHnZrl3CFY@joel-zenbook


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>