MIPS: JZ4740: read intc base address from DT

Read the base address of the SoC interrupt controller from the device
tree rather than relying upon the JZ4740_INTC_BASE_ADDR macro, in order
to remove the dependency on the asm/mach-jz4740/base.h header.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Brian Norris <computersforpeace@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/10145/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>