e1000e: Separate TGP board type from SPT

[ Upstream commit 280db5d4

 ]

We have the same LAN controller on different PCHs. Separate TGP board
type from SPT which will allow for specific fixes to be applied for
TGP platforms.

Suggested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Tested-by: Mark Pearson <markpearson@lenovo.com>
Tested-by: Nechama Kraus <nechamax.kraus@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>