parisc: remove ARCH_DEFCONFIG

Commit 2a86f661 ("kbuild: use KBUILD_DEFCONFIG as the fallback for
DEFCONFIG_LIST") removed ARCH_DEFCONFIG because it does not make much
sense.

In the same development cycle, Commit ededa081 ("parisc: Fix
defconfig selection") added ARCH_DEFCONFIG for parisc.

Please use KBUILD_DEFCONFIG in arch/*/Makefile for defconfig selection.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/Kconfig

@@ -85,11 +85,6 @@ config MMU
 config STACK_GROWSUP
 	def_bool y
 
-config ARCH_DEFCONFIG
-	string
-	default "arch/parisc/configs/generic-32bit_defconfig" if !64BIT
-	default "arch/parisc/configs/generic-64bit_defconfig" if 64BIT
-
 config GENERIC_LOCKBREAK
 	bool
 	default y