ArmVirtPkg: Make terminal type consistent

ArmVirtPkg: Make terminal type consistent

Change default terminal type to be consistent with default
ConIn/ConOut device path, which is now determined by TTY_TERMINAL
flag, TTYTERM or VT100.

I can't say this is a bug, as we can pass the whole console device
path to ConnectController, and TerminalDxe driver will pick up the
terminal in the remaining device path. However, in rare circumstances,
the console devices may be disconnected with the driver, and they will
be ignored by ConPlatformDxe until we pass the device path explicitly
just as BDS.

Changing default terminal type to be the same with console device
path could help serial terminal be reconnected with normal connect
controller operation.

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Heyi Guo <heyi.guo@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18025 6f19259b-4bc3-4df7-8a09-765794883524