busybox: ensure SHA passwords are supported if used

As reported on IRC, our default busybox configuration doesn't support SHA
encoded passwords, breaking login if enabled under system configuration.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/busybox/busybox.mk

@@ -75,6 +75,13 @@ define BUSYBOX_SET_MDEV
 endef
 endif
 
+# sha passwords need USE_BB_CRYPT_SHA
+ifeq ($(BR2_TARGET_GENERIC_PASSWD_SHA256)$(BR2_TARGET_GENERIC_PASSWD_SHA512),y)
+define BUSYBOX_SET_CRYPT_SHA
+	$(call KCONFIG_ENABLE_OPT,CONFIG_USE_BB_CRYPT_SHA,$(BUSYBOX_BUILD_CONFIG))
+endef
+endif
+
 ifeq ($(BR2_USE_MMU),y)
 define BUSYBOX_SET_MMU
 	$(call KCONFIG_DISABLE_OPT,CONFIG_NOMMU,$(BUSYBOX_BUILD_CONFIG))
@@ -182,6 +189,7 @@ define BUSYBOX_CONFIGURE_CMDS
 	$(BUSYBOX_SET_IPV6)
 	$(BUSYBOX_PREFER_STATIC)
 	$(BUSYBOX_SET_MDEV)
+	$(BUSYBOX_SET_CRYPT_SHA)
 	$(BUSYBOX_NETKITBASE)
 	$(BUSYBOX_NETKITTELNET)
 	$(BUSYBOX_INTERNAL_SHADOW_PASSWORDS)