Its only callers are inside pnv_phb4.c.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220111131027.599784-6-danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>