serial: 8250_tegra: Create Tegra specific 8250 driver

To support booting NVIDIA Tegra platforms with either Device-Tree or
ACPI, create a Tegra specific 8250 serial driver that supports both
firmware types. Another benefit from doing this, is that the Tegra
specific codec in the generic Open Firmware 8250 driver can now be
removed.

Signed-off-by: Jeff Brasen <jbrasen@nvidia.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200129132817.26343-1-jonathanh@nvidia.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>