pwm: lp3943: Fix an incorrect type in lp3943_pwm_parse_dt()

pwm: lp3943: Fix an incorrect type in lp3943_pwm_parse_dt()

The return value from the call to of_property_count_u32_elems() is int.
However, the return value is being assigned to an u32 variable
'num_outputs', so making 'num_outputs' an int.

./drivers/pwm/pwm-lp3943.c:238:6-17: WARNING: Unsigned expression compared with zero: num_outputs <= 0.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9710
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Fixes: 75f0cb339b78 ("pwm: lp3943: Use of_property_count_u32_elems() to get property length")
Link: https://lore.kernel.org/r/20240809080523.32717-1-jiapeng.chong@linux.alibaba.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>