binman: Add renesas_rcar4_sa0 etype

Add new etype which generates the Renesas R-Car Gen4 SA0 header.
This header is placed at the beginning of SPI NOR and describes
where should data from SPI NOR offset 0x40000 be loaded to, and
how much data should be loaded there. In case of U-Boot, this is
used to load SPL and possibly other payload(s) into RT-VRAM.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

.gitignore

@@ -75,6 +75,7 @@ fit-dtb.blob*
 /keep-syms-lto.*
 /*imx8mimage*
 /*imx8mcst*
+/*rcar4-sa0*
 /drivers/video/u_boot_logo.S
 /test/overlay/test-fdt-overlay.dtbo.S
 /test/overlay/test-fdt-overlay-stacked.dtbo.S