When writing a register from the TCTXT memory region (4th page within
the IC BAR), we were overwriting the Presentation Controller (PC)
register at the same offset. It looks like a silly cut and paste
error.

We were somehow lucky: the TCTXT registers being touched are
TCTXT_ENx/_SET/_RESET to enable physical threads and the PC registers
at the same offset are either not used by our model or the update was
harmless.

Found through code inspection.

Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20220523151859.72283-1-fbarrat@linux.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>