MIPS: add support for M5100 cores

-march=m5100 support starts from GCC-6, so disable previous versions
when selecting this core.

Note that M5100 implies a MIPS R5 CPU, and some GCC versions are already
disabled for R5, so we don't need to disable those ones for M5100 as
well.

Also disable external toolchains that don't support this core.

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

arch/Config.in.mips

@@ -47,6 +47,10 @@ config BR2_mips_interaptiv
 	bool "interAptiv"
 	depends on !BR2_ARCH_IS_64
 	select BR2_MIPS_CPU_MIPS32R2
+config BR2_mips_m5100
+	bool "M5100"
+	depends on !BR2_ARCH_IS_64
+	select BR2_MIPS_CPU_MIPS32R5
 config BR2_mips_64
 	bool "Generic MIPS64"
 	depends on BR2_ARCH_IS_64
@@ -109,6 +113,7 @@ config BR2_GCC_TARGET_ARCH
 	default "mips32r5"	if BR2_mips_32r5
 	default "mips32r6"	if BR2_mips_32r6
 	default "interaptiv"	if BR2_mips_interaptiv
+	default "m5100"		if BR2_mips_m5100
 	default "mips64"	if BR2_mips_64
 	default "mips64r2"	if BR2_mips_64r2
 	default "mips64r5"	if BR2_mips_64r5

package/gcc/Config.in.host

@@ -100,7 +100,7 @@ choice
 		# musl ppc64 unsupported
 		depends on !(BR2_TOOLCHAIN_USES_MUSL && (BR2_powerpc64 || BR2_powerpc64el))
 		# Unsupported MIPS cores
-		depends on !BR2_mips_interaptiv
+		depends on !BR2_mips_interaptiv && !BR2_mips_m5100
 		# musl mips64 unsupported
 		depends on !(BR2_TOOLCHAIN_USES_MUSL && (BR2_mips64 || BR2_mips64el))
 		select BR2_GCC_NEEDS_MPC

toolchain/toolchain-external/Config.in

@@ -598,7 +598,7 @@ config BR2_TOOLCHAIN_EXTERNAL_MUSL_CROSS
 		BR2_x86_64
 	depends on BR2_HOSTARCH = "x86_64" || BR2_HOSTARCH = "x86"
 	# Unsupported MIPS cores
-	depends on !BR2_mips_interaptiv
+	depends on !BR2_mips_interaptiv && !BR2_mips_m5100
 	# Unsupported for MIPS R6
 	depends on !BR2_MIPS_CPU_MIPS32R6 && !BR2_MIPS_CPU_MIPS64R6
 	select BR2_TOOLCHAIN_EXTERNAL_MUSL