powerpc/32: Add ppc_defconfig

Add a generic 32-bit defconfig called ppc_defconfig. This means we'll
have a defconfig matching "uname -m" for all cases.

This config is mostly intended for build testing but if someone wants
to tweak it to get it booting on something that would be fine too.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/Makefile

@@ -367,6 +367,10 @@ ppc32_allmodconfig:
 	$(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/book3s_32.config \
 		-f $(srctree)/Makefile allmodconfig
 
+PHONY += ppc_defconfig
+ppc_defconfig:
+	$(call merge_into_defconfig,book3s_32.config,)
+
 PHONY += ppc64le_allmodconfig
 ppc64le_allmodconfig:
 	$(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/le.config \