Add some quick local {cross}build scripts

Simple wrappers around using rpmbuild to turn off various things.  In th arm
cases, we can't cross build perf or tools anyway.

scripts/cross-aarch64

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+rpmbuild --target aarch64 --with cross --without debuginfo --without perf --without tools --define "__strip /usr/bin/aarch64-linux-gnu-strip" --rebuild $1

scripts/cross-arm

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+rpmbuild --target armv7hl --with cross --without debuginfo --without perf --without tools --define "__strip /usr/bin/arm-linux-gnu-strip" --rebuild $1

scripts/fast-x86_64

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+rpmbuild --target x86_64 --without debuginfo --without perf --without tools --rebuild $1