[media] lirc_parallel: avoid name conflict on mn10300 arch

[media] lirc_parallel: avoid name conflict on mn10300 arch

The "irq_handler" name is already defined there on a header
file:

/devel/v4l/temp/drivers/staging/media/lirc/lirc_parallel.c:223:13: error: conflicting types for ‘irq_handler’
 static void irq_handler(void *blah)
             ^
In file included from /devel/v4l/temp/arch/mn10300/include/asm/reset-regs.h:16:0,
                 from /devel/v4l/temp/arch/mn10300/include/asm/irq.h:18,
                 from /devel/v4l/temp/include/linux/irq.h:24,
                 from /devel/v4l/temp/arch/mn10300/include/asm/hardirq.h:16,
                 from /devel/v4l/temp/include/linux/preempt_mask.h:5,
                 from /devel/v4l/temp/include/linux/sched.h:25,
                 from /devel/v4l/temp/include/linux/utsname.h:5,
                 from /devel/v4l/temp/arch/mn10300/include/asm/elf.h:15,
                 from /devel/v4l/temp/include/linux/elf.h:4,
                 from /devel/v4l/temp/include/linux/module.h:14,
                 from /devel/v4l/temp/drivers/staging/media/lirc/lirc_parallel.c:29:
/devel/v4l/temp/arch/mn10300/include/asm/exceptions.h:107:24: note: previous declaration of ‘irq_handler’ was here
 extern asmlinkage void irq_handler(void);

/devel/v4l/patchwork/drivers/staging/media/lirc/lirc_serial.c:653:20: error: conflicting types for ‘irq_handler’
 static irqreturn_t irq_handler(int i, void *blah)
                    ^
In file included from /devel/v4l/patchwork/arch/mn10300/include/asm/reset-regs.h:16:0,
                 from /devel/v4l/patchwork/arch/mn10300/include/asm/irq.h:18,
                 from /devel/v4l/patchwork/include/linux/irq.h:24,
                 from /devel/v4l/patchwork/arch/mn10300/include/asm/hardirq.h:16,
                 from /devel/v4l/patchwork/include/linux/preempt_mask.h:5,
                 from /devel/v4l/patchwork/include/linux/sched.h:25,
                 from /devel/v4l/patchwork/include/linux/utsname.h:5,
                 from /devel/v4l/patchwork/arch/mn10300/include/asm/elf.h:15,
                 from /devel/v4l/patchwork/include/linux/elf.h:4,
                 from /devel/v4l/patchwork/include/linux/module.h:14,
                 from /devel/v4l/patchwork/drivers/staging/media/lirc/lirc_serial.c:53:
/devel/v4l/patchwork/arch/mn10300/include/asm/exceptions.h:107:24: note: previous declaration of ‘irq_handler’ was here
 extern asmlinkage void irq_handler(void);

So, rename it, to avoid namespace conflicts.

This patch fixes building media drivers with allyesconfig/almodconfig on
mn10300 arch.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>