vim/vim-tiny: fix multiple .bb files provide xxd

Since the following commit applied:
...
commit 34988c5319
Author: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Date:   Wed Jul 18 10:14:51 2018 +0200

    vim: provide xxd
...

And vim-tiny recipe contains vim reicpe, it caused both of
them provides xxd. Add `${PN}' prefix to it.

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-support/vim/vim_8.1.0172.bb

@@ -112,4 +112,4 @@ ALTERNATIVE_PRIORITY = "100"
 
 BBCLASSEXTEND = "native"
 
-PROVIDES += "xxd"
+PROVIDES += "${PN}-xxd"