lvconvert/lvcreate: raise maximum number of raid images
Because of contraints in renaming shifted rimage/rmeta LV names
the current RaidLV limit is a maximum of 10 SubLV pairs.
With the previous introduction of reshaping infratructure that
constriant got removed.
Kernel supports 253 since dm-raid target 1.9.0, older kernels 64.
Raise the maximum number of RaidLV rimage/rmeta pairs to 64.
If we want to raise past 64, we have to introdce a check for
the kernel supporting it in lvcreate/lvconvert.