nuttx/arch: select ARCH_HAVE_TESTSET if ARCH_HAVE_CUSTOM_TESTSET is on

the include/nuttx/spinlock.h#up_testset() function is also controlled by
ARCH_HAVE_TESTSET, so when ARCH_HAVE_CUSTOM_TESTSET is selected by
boards, the include/nuttx/spinlock.h#up_testset() should also not be
build, and using the board specific implementation.
So in this case, if Option ARCH_HAVE_CUSTOM_TESTSET is enabled,
it is assumed that Option ARCH_HAVE_TESTSET is also enabled.
However, when Option ARCH_HAVE_TESTSET is enabled, it doesn't necessarily
mean that Option ARCH_HAVE_CUSTOM_TESTSET is also enabled.
In this way, it can be ensured that the implementation under the
include/nuttx/spinlock.h#up_testset can also be controlled by
Option ARCH_HAVE_CUSTOM_TESTSET.

Signed-off-by: guoshichao <guoshichao@xiaomi.com>

arch/Kconfig

@@ -487,6 +487,7 @@ config ARCH_HAVE_TESTSET
 config ARCH_HAVE_CUSTOM_TESTSET
 	bool
 	default n
+	select ARCH_HAVE_TESTSET
 
 config ARCH_HAVE_THREAD_LOCAL
 	bool