powerpc/pseries/lpar: convert to papr_sysparm API

Convert the TLB block invalidate characteristics discovery to the new
papr_sysparm API. This occurs too early in boot to use
papr_sysparm_buf_alloc(), so use a static buffer.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-18-26929c8cce78@linux.ibm.com