package/rt-tests: bump to version 1.8

package/rt-tests: bump to version 1.8

Drop patch #1. libnuma is now a mandatory dependency. The ostype and
machinetype variables are not used for the Linux target.

Drop patch #3. SH is not a supported target architecture anymore.

Add mandatory dependency on libnuma (numactl). Propagate numactl
architecture dependency.

Update homepage link. The kernel wiki is dead.

Drop Python build time dependency. Python is an optional run-time
dependency.

Add reference to upstream provided tarball hash.

Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>