mps2-an500/knsh: disable SPINLOCK to avoid build break

workaround for remove libc depends from kernel api

build break on phase 2 userspace link:

| arm-none-eabi-ld -o nuttx_user.elf --undefined=nsh_main --entry=nsh_main -T /nuttx/boards/arm/mps/mps2-an500/scripts/memory.ld \
| -T /nuttx/boards/arm/mps/mps2-an500/scripts/user-space.ld -L/nuttx/staging/ -L/nuttx/staging/ -L/nuttx/staging/ -L/nuttx/staging/ \
| -L/nuttx/staging/ -L/nuttx/staging/ mps_userspace.o --start-group -lproxies -lc -lmm -larch -lxx -lapps --end-group \
| "prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/thumb/v7e-m+fp/hard/libgcc.a"
|
| arm-none-eabi-ld: /nuttx/staging//libc.a(lib_pathbuffer.o): in function `spin_unlock_wo_note':
| /nuttx/include/nuttx/spinlock.h:380:(.text.lib_get_pathbuffer+0x298): undefined reference to `g_irq_spin_count'
| arm-none-eabi-ld: /nuttx/include/nuttx/spinlock.h:380:(.text.lib_get_pathbuffer+0x29c): undefined reference to `g_irq_spin'
| arm-none-eabi-ld: /nuttx/staging//libc.a(lib_pathbuffer.o): in function `lib_put_pathbuffer':
| /nuttx/libs/libc/misc/lib_pathbuffer.c:147:(.text.lib_put_pathbuffer+0x210): undefined reference to `g_irq_spin_count'
| arm-none-eabi-ld: /nuttx/libs/libc/misc/lib_pathbuffer.c:147:(.text.lib_put_pathbuffer+0x214): undefined reference to `g_irq_spin'
| make[1]: *** [Makefile:61: nuttx_user.elf] Error 1
| make[1]: Leaving directory '/nuttx/boards/arm/mps/mps2-an500/kernel'
| make: *** [tools/Unix.mk:540: nuttx] Error 2

Signed-off-by: chao an <anchao@lixiang.com>

boards/arm/mps/mps2-an500/configs/knsh/defconfig

@@ -61,7 +61,6 @@ CONFIG_READLINE_CMD_HISTORY=y
 CONFIG_RR_INTERVAL=200
 CONFIG_SCHED_HPWORK=y
 CONFIG_SCHED_HPWORKPRIORITY=192
-CONFIG_SPINLOCK=y
 CONFIG_STACK_COLORATION=y
 CONFIG_STANDARD_SERIAL=y
 CONFIG_START_DAY=25