mfd: sun4i-gpadc: Correct specified GPADC interrupt numbers

mfd: sun4i-gpadc: Correct specified GPADC interrupt numbers

The identifiers are used as IRQ resource numbers, where 0 is treated
specially.

This fixes sun4i-gpadc-iio probe failed when request irq.

The backstack:
	WARNING: CPU: 3 PID: 1 at drivers/base/platform.c:451
	__platform_get_irq_byname+0xb8/0xc4
	0 is an invalid IRQ number
	Modules linked in:
	CPU: 3 PID: 1 Comm: swapper/0 Not tainted 6.7.0-rc6 #9
	Hardware name: Allwinner sun8i Family
	 unwind_backtrace
	 show_stack
	 dump_stack_lvl
	 __warn
	 warn_slowpath_fmt
	 __platform_get_irq_byname
	 platform_get_irq_byname
	 sun4i_irq_init
	 sun4i_gpadc_probe
	 platform_probe
	 really_probe
	 __driver_probe_device
	 driver_probe_device
	 __driver_attach
	 bus_for_each_dev
	 bus_add_driver
	 driver_register
	 do_one_initcall
	 do_initcall_level
	 do_initcalls
	 kernel_init_freeable
	 kernel_init

Log reports:
sun4i-gpadc-iio sun6i-a31-gpadc-iio.0: error -EINVAL: IRQ FIFO_DATA_PENDING
not found
sun4i-gpadc-iio: probe of sun6i-a31-gpadc-iio.0 failed with error -22

Signed-off-by: Fuyao Kashizuku <fuyao@sjterm.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/ZYuFbUUus9apiCpq@debian.cyg
Signed-off-by: Lee Jones <lee@kernel.org>