mfgtools: add gcc version dependency

MfgTools requires gcc >= 4.8 since it needs C++11 support.

Fixes the following autobuild issues:
http://autobuild.buildroot.net/results/c8cbc4e5296af91be5fa8b17871bedf08b6a2697
http://autobuild.buildroot.net/results/fadabb38d8dde6f2be85fbc286b060e2f3e82f65

Signed-off-by: Gary Bisson <gary.bisson@boundarydevices.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/mfgtools/Config.in.host

@@ -1,6 +1,10 @@
+comment "mfgtools needs host gcc >= 4.8"
+	depends on !BR2_HOST_GCC_AT_LEAST_4_8
+
 config BR2_PACKAGE_HOST_MFGTOOLS
 	bool "host mfgtools"
 	depends on BR2_arm
+	depends on BR2_HOST_GCC_AT_LEAST_4_8 # needs C++11
 	help
 	  This package contains the Freescale manufacturing tool.
 	  It is designed to program firmware to i.MX boards during