mb/google/octopus: Create phaser variant

This creates a phaser variant for octopus. Nothing is set in the variant
files here; everything is picked up from baseboard.

BUG=b:78572180
TEST=None

Change-Id: Ia03e8af91741f1f7aa3a42ac28688b8b6a708932
Signed-off-by: Justin TerAvest <teravest@chromium.org>
Reviewed-on: https://review.coreboot.org/25877
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

src/mainboard/google/octopus/Kconfig.name

@@ -10,3 +10,7 @@ config BOARD_GOOGLE_BIP
 	bool "Bip"
 	select BOARD_GOOGLE_BASEBOARD_OCTOPUS
 	select BASEBOARD_OCTOPUS_LAPTOP
+config BOARD_GOOGLE_PHASER
+	bool "Phaser"
+	select BOARD_GOOGLE_BASEBOARD_OCTOPUS
+	select BASEBOARD_OCTOPUS_LAPTOP