[PATCH v8 13/13] arm64: defconfig: Enable OF_OVERLAY option

[Andrea della Porta <andrea.porta@xxxxxxxx>]

The RP1 driver uses the infrastructure enabled by OF_OVERLAY config
option. Enable that option in defconfig in order to produce a kernel
usable on RaspberryPi5 avoiding to enable it separately.

Signed-off-by: Andrea della Porta <andrea.porta@xxxxxxxx>
---
The following metrics should help to decide whether this patch is
acceptable or not. The defconfig kernel with CONFIG_OF_OVERLAY=y
added (wrt to the defconfig one without that set) has:

- same uncompressed kernel image size (due to ELF section alignment I guess)

- ~7Kb bigger Image.gz

- 3 new modules (all related to RP1, i.e.: clk-rp1, pinctrl-rp1 and rp1-pci)

- 27 added symbols, of which 5 exported
 
hoping this is enough to gather a rough idea of the impact.
Please note that OF_OVERLAY has to be defined in a way or another,
otherwise the RP1 driver won't work correctly in case the dtb overlay
embedded into the driver is used.
Another way would be to add a phony target to the arm64 makefile which
just add that config option to the target.
---
 arch/arm64/configs/defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index cc70793e97ef..ca492fbd2773 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -1643,6 +1643,7 @@ CONFIG_FPGA_BRIDGE=m
 CONFIG_ALTERA_FREEZE_BRIDGE=m
 CONFIG_FPGA_REGION=m
 CONFIG_OF_FPGA_REGION=m
+CONFIG_OF_OVERLAY=y
 CONFIG_TEE=y
 CONFIG_OPTEE=y
 CONFIG_MUX_GPIO=m
-- 
2.35.3