ARM: add multi_v7_lpae_defconfig

The only missing configuration option preventing us from using
multi_v7_defconfig with the Raspberry Pi 4 is ARM_LPAE. It's needed as
the PCIe controller found on the SoC depends on 64bit addressing, yet
can't be included as not all v7 boards support LPAE.

Introduce multi_v7_lpae_defconfig, built off multi_v7_defconfig, which will
avoid us having to duplicate and maintain multiple similar configurations.

Needless to say the Raspberry Pi 4 is not the only platform that can
benefit from this new configuration.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20230124110213.3221264-11-alexander.stein@ew.tq-group.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/Makefile

@@ -319,6 +319,10 @@ endif
 # My testing targets (bypasses dependencies)
 bp:;	$(Q)$(MAKE) $(build)=$(boot) $(boot)/bootpImage
 
+include $(srctree)/scripts/Makefile.defconf
+PHONY += multi_v7_lpae_defconfig
+multi_v7_lpae_defconfig:
+	$(call merge_into_defconfig,multi_v7_defconfig,lpae)
 
 define archhelp
   echo  '* zImage        - Compressed kernel image (arch/$(ARCH)/boot/zImage)'
@@ -334,4 +338,6 @@ define archhelp
   echo  '                  (distribution) /sbin/$(INSTALLKERNEL) or'
   echo  '                  install to $$(INSTALL_PATH) and run lilo'
   echo  '  vdso_install  - Install unstripped vdso.so to $$(INSTALL_MOD_PATH)/vdso'
+  echo
+  echo  '  multi_v7_lpae_defconfig     - multi_v7_defconfig with CONFIG_ARM_LPAE enabled'
 endef

arch/arm/configs/lpae.config

@@ -0,0 +1,2 @@
+CONFIG_ARM_LPAE=y
+CONFIG_VMSPLIT_2G=y