net: stmmac: move stmmac_get_*id() into stmmac_get_version()

net: stmmac: move stmmac_get_*id() into stmmac_get_version()

Move the contents of both stmmac_get_id() and stmmac_get_dev_id() into
stmmac_get_version() as it no longer makes sense for these to be
separate functions.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Tested-by: Mohd Ayaan Anwar <mohd.anwar@oss.qualcomm.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1vDtew-0000000CCC9-0KeM@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>