Config.uk: Correct libc dependency

Previously libuuid would hard-select libnewlibc as it requires a libc.
This change eases this restriction into a dependency on any libc.

Signed-off-by: Andrei Tatar <andrei@unikraft.io>
Reviewed-by: Radu Nichita <radunichita99@gmail.com>
Reviewed-by: Stefan Jumarea <stefanjumarea02@gmail.com>
Approved-by: Razvan Deaconescu <razvand@unikraft.io>
Tested-by: Unikraft CI <monkey@unikraft.io>
GitHub-Closes: #4

Author: andreittr

Config.uk

@@ -1,7 +1,7 @@
 config LIBUUID
 	bool "libuuid - library for unique id generation"
 	default n
-	select LIBNEWLIBC
+	depends on HAVE_LIBC
 	select LIBPOSIX_USER
 	select LIBUKTIME