x86: add generic image, use ext4 filesystem

targets/x86-generic/profiles.mk

+$(eval $(call GluonProfile,GENERIC))
+$(eval $(call GluonProfileFactorySuffix,GENERIC))
+$(eval $(call GluonProfileSysupgradeSuffix,GENERIC))
+$(eval $(call GluonProfileExtraSuffix,GENERIC,.img.gz))
+$(eval $(call GluonModel,GENERIC,combined-ext4,x86-generic))
+
 $(eval $(call GluonProfile,VDI,kmod-pcnet32))
 $(eval $(call GluonProfileFactorySuffix,VDI))
 $(eval $(call GluonProfileSysupgradeSuffix,VDI))
 $(eval $(call GluonProfileExtraSuffix,VDI,.vdi))
-$(eval $(call GluonModel,VDI,combined-squashfs,x86-virtualbox))
+$(eval $(call GluonModel,VDI,combined-ext4,x86-virtualbox))
 
 $(eval $(call GluonProfile,VMDK,kmod-pcnet32))
 $(eval $(call GluonProfileFactorySuffix,VMDK))
 $(eval $(call GluonProfileSysupgradeSuffix,VMDK))
 $(eval $(call GluonProfileExtraSuffix,VMDK,.vmdk))
-$(eval $(call GluonModel,VMDK,combined-squashfs,x86-vmware))
+$(eval $(call GluonModel,VMDK,combined-ext4,x86-vmware))