net: stmmac: move stmmac_init_ptp() messages into function

Move the stmmac_init_ptp() messages from stmmac_hw_setup() to
stmmac_init_ptp(), which will allow further cleanups.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>