sched/signal: Add support to disable partial signals

[wangchdo]

Summary

sched/signal: Add support to disable partial signals

Fix dependency issue when signals are only partially enabled

Co-authored-by: guoshichao guoshichao@xiaomi.com
Signed-off-by: Chengdong Wang wangchengdong@lixiang.com

Impact

Fix dependency issue when signals are only partially enabled

Testing

ostest passed on rv-virt:smp64 when CONFIG_ENABLE_PARTIAL_SIGNALS=y

nsh> uname -a
NuttX 0.0.0 3503bbec44-dirty Dec 23 2025 11:32:43 risc-v rv-virt
nsh> ostest

(...)

smp_call_test: Call cpu 1, wait
smp_call_test: Call cpu 2, nowait
smp_call_test: Call cpu 2, wait
smp_call_test: Call cpu 3, nowait
smp_call_test: Call cpu 3, wait
smp_call_test: Call cpu 4, nowait
smp_call_test: Call cpu 4, wait
smp_call_test: Call cpu 5, nowait
smp_call_test: Call cpu 5, wait
smp_call_test: Call cpu 6, nowait
smp_call_test: Call cpu 6, wait
smp_call_test: Call cpu 7, nowait
smp_call_test: Call cpu 7, wait
smp_call_test: Call multi cpu, nowait
smp_call_test: Call in interrupt, wait
smp_call_test: Call multi cpu, wait
smp_call_test: Test success

Final memory usage:
VARIABLE  BEFORE   AFTER
======== ======== ========
arena     1fc23e0  1fc23e0
ordblks         1        7
mxordblk  1fb72f0  1fa4140
uordblks     b0f0    14df8
fordblks  1fb72f0  1fad5e8
user_main: Exiting
ostest_main: Exiting with status 0