target/ppc: fix timebase register reset state

target/ppc: fix timebase register reset state

(H)DEC and PURR get reset before icount does, which causes them to be
skewed and not match the init state. This can cause replay to not
match the recorded trace exactly. For DEC and HDEC this is usually not
noticable since they tend to get programmed before affecting the
target machine. PURR has been observed to cause replay bugs when
running Linux.

Fix this by resetting using a time of 0.

Message-ID: <20241219034035.1826173-2-npiggin@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>