clocksource/drivers/sun5i: Remove surplus dev_err() when using platform_get_irq()

There is no need to call the dev_err() function directly to print a
custom message when handling an error from either the platform_get_irq()
or platform_get_irq_byname() functions as both are going to display an
appropriate error message in case of a failure.

./drivers/clocksource/timer-sun5i.c:260:2-9: line 260 is redundant because platform_get_irq() already prints an error

Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230831041414.66434-1-yang.lee@linux.alibaba.com