Remove specific dependencies and let RPM auto-generate the dependencies on libraries during build.

Signed-off-by: Avi Miller <avi.miller@oracle.com>

hack/make/.build-rpm/docker-engine.spec

@@ -37,10 +37,7 @@ Requires(preun): initscripts
 # required packages on install
 Requires: /bin/sh
 Requires: iptables
-Requires: libc.so.6
 Requires: libcgroup
-Requires: libpthread.so.0
-Requires: libsqlite3.so.0
 Requires: tar
 Requires: xz
 %if 0%{?fedora} >= 21