package_rpm.bbclass: improve reproducibility of RPM packages

package_rpm.bbclass: improve reproducibility of RPM packages

The RPM packages contain BUILDHOST based on the current build host.
This breaks reproducibility if the same package is build on two different hosts.
To improve reproducible builds, we always set BUILDHOST as "reproducible".

(From OE-Core rev: f3beb683380ec0d9efa0d6af83205350afd1b2de)

Signed-off-by: Juro Bystricky <juro.bystricky@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>