intel: genxml: decode variable length MI_LRI

intel: genxml: decode variable length MI_LRI

MI_LOAD_REGISTER_IMM can load multiple (register, value) tuples in one
command. In our drivers we only use one tuple at a time, but the
kernel might load more than one at a time.

Instead of making all the tuple part of a group, we leave out the
first tuple (the one we use in the generated packing structures).

This is particularly useful for looking at error stats generated by
the kernel.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Scott D Phillips <scott.d.phillips@intel.com>