[S390] Use IPL CLEAR for reipl under z/VM
[S390] Use IPL CLEAR for reipl under z/VM

If we use the CLEAR ipl option, reipl is faster, since then VM can release
the memory, which has been paged out.

Signed-off-by: Michael Holzheu <db4757c56f54651f568cc7cda79cd93c781b1605@de.ibm.com>
Signed-off-by: Martin Schwidefsky <52616596d8f5df0d597e85ab515377f92f939c68@de.ibm.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas