pcsp - Don't build pcspkr when snd-pcsp is enabled

- Update CREDITS with the pc-speaker driver authors.
- Prevent pcspkr from being built together with snd-pcsp.
  Both pcspkr and snd-pcsp use the same platform driver name "pcspkr".

Signed-off-by: Stas Sergeev <stsp@aknet.ru>
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index c5263d6..92b6834 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -15,6 +15,7 @@
 config INPUT_PCSPKR
 	tristate "PC Speaker support"
 	depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
+	depends on SND_PCSP=n
 	help
 	  Say Y here if you want the standard PC Speaker to be used for
 	  bells and whistles.