char: tpm: nuvoton: remove unused variable

“wait” wait queue is defined but never used in the function, thus
it can be removed.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Acked-By: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>