libsigsegv: mark as not available on m68k

Fixes:

  http://autobuild.buildroot.net/results/059fd862bd3e9456783f2f4ba307df15dbab0d41/

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

package/libsigsegv/Config.in

@@ -3,6 +3,7 @@ config BR2_PACKAGE_LIBSIGSEGV
 	depends on !BR2_xtensa
 	depends on !BR2_arc # no ucontext_i.sym file
 	depends on !BR2_microblaze
+	depends on !BR2_m68k # unknown type name 'ucontext_t'
 	# No ucontext support in uclibc for powerpc and superh
 	depends on !((BR2_powerpc || BR2_sh) && BR2_TOOLCHAIN_USES_UCLIBC)
 	help