superio/nuvoton: Factor out equivalent Kconfig option

There's no need to have multiple Kconfig symbols which do the same
thing. Introduce `SUPERIO_NUVOTON_COMMON_COM_A` and update boards to use
the new symbol. To preserve alphabetical order in mainboard Kconfig,
place the new symbol above the Super I/O symbol (instead of below).

Change-Id: Ic0a30b3177a1a535261525638be301ae07c59c14
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46522
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/asrock/h81m-hds/Kconfig b/src/mainboard/asrock/h81m-hds/Kconfig
index 6406417..af723a3 100644
--- a/src/mainboard/asrock/h81m-hds/Kconfig
+++ b/src/mainboard/asrock/h81m-hds/Kconfig
@@ -17,8 +17,8 @@
 	select RT8168_SET_LED_MODE
 	select SERIRQ_CONTINUOUS_MODE
 	select SOUTHBRIDGE_INTEL_LYNXPOINT
+	select SUPERIO_NUVOTON_COMMON_COM_A
 	select SUPERIO_NUVOTON_NCT6776
-	select SUPERIO_NUVOTON_NCT6776_COM_A
 
 config CBFS_SIZE
 	hex