toolchain-buildroot: don't show musl on noMMU platforms

While musl has recently gained noMMU support for the sh2 platform, we
don't support this yet. So for the time being, let's not show musl as
an available C library on noMMU platforms. This is for example
important on ARM noMMU: ARM is supported by musl, but not its noMMU
variants.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

toolchain/toolchain-buildroot/Config.in

@@ -94,6 +94,9 @@ config BR2_TOOLCHAIN_BUILDROOT_MUSL
 	depends on !BR2_powerpc_SPE # not supported, build breaks
 	# Unsupported for MIPS R6
 	depends on !BR2_mips_32r6 && !BR2_mips_64r6
+	# sh2 nommu is supported by musl, but we don't have support
+	# for it in Buildroot.
+	depends on BR2_USE_MMU
 	select BR2_TOOLCHAIN_USES_MUSL
 	help
 	  This option selects musl as the C library for the