arm/clang: clang must depends on the implementation of the math library

Since picolibc used by clang-17 does not provide an implementation of libm,
if you want to use clang, please must specify a libm as an option.

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

Author: anchao

arch/arm/Kconfig

@@ -40,6 +40,7 @@ config ARM_TOOLCHAIN_GNU_OABI
 
 config ARM_TOOLCHAIN_CLANG
 	bool "LLVM Clang toolchain"
+	depends on !LIBM_TOOLCHAIN && !LIBM_NONE
 	select ARCH_TOOLCHAIN_CLANG
 
 config ARM_TOOLCHAIN_ARMCLANG