MIPS: Alchemy: remove all CONFIG_SOC_AU1??? defines

Now that no driver any longer depends on the CONFIG_SOC_AU1???  symbols,
it's time to get rid of them: Move some of the platform devices to the
boards which can use them, Rename a few (unused) constants in the header,
Replace them with MIPS_ALCHEMY in the various Kconfig files.  Finally
delete them altogether from the Alchemy Kconfig file.

Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com>
To: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/2707/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/sound/soc/au1x/Kconfig b/sound/soc/au1x/Kconfig
index 4b67140..606039f 100644
--- a/sound/soc/au1x/Kconfig
+++ b/sound/soc/au1x/Kconfig
@@ -3,7 +3,7 @@
 ##
 config SND_SOC_AU1XPSC
 	tristate "SoC Audio for Au1200/Au1250/Au1550"
-	depends on SOC_AU1200 || SOC_AU1550
+	depends on MIPS_ALCHEMY
 	help
 	  This option enables support for the Programmable Serial
 	  Controllers in AC97 and I2S mode, and the Descriptor-Based DMA