powerpc/configs: Add a powernv_be_defconfig

Although pretty much everyone using powernv is running little endian,
we should still test we can build for big endian. So add a
powernv_be_defconfig, which is autogenerated by flipping the endian
symbol in powernv_defconfig.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>

arch/powerpc/Makefile

@@ -316,6 +316,10 @@ PHONY += ppc64le_defconfig
 ppc64le_defconfig:
 	$(call merge_into_defconfig,ppc64_defconfig,le)
 
+PHONY += powernv_be_defconfig
+powernv_be_defconfig:
+	$(call merge_into_defconfig,powernv_defconfig,be)
+
 PHONY += mpc85xx_defconfig
 mpc85xx_defconfig:
 	$(call merge_into_defconfig,mpc85xx_basic_defconfig,\

arch/powerpc/configs/be.config

+CONFIG_CPU_BIG_ENDIAN=y