tar: adjust Config.in comment dependency

Since commit 916b21a7fbf266f452b8dc4116133cc57fdad269 ("package/tar:
Depends on MMU"), BR2_PACKAGE_TAR depends on BR2_USE_MMU. However, the
Config.in comment does not take into account this dependency, an
inconsistency which is fixed by this commit.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 2a3ef05520a6764fae0277a36014b011765ac3d9)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/tar/Config.in

@@ -12,4 +12,5 @@ config BR2_PACKAGE_TAR
 
 comment "tar needs a toolchain w/ wchar"
 	depends on !BR2_USE_WCHAR
+	depends on BR2_USE_MMU
 	depends on BR2_PACKAGE_BUSYBOX_SHOW_OTHERS