global: Use proper project name U-Boot

Use proper project name in comments, Kconfig, readmes.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/0dbdf0432405c1c38ffca55703b6737a48219e79.1684307818.git.michal.simek@amd.com
diff --git a/common/spl/spl.c b/common/spl/spl.c
index 72078a8..28124a8 100644
--- a/common/spl/spl.c
+++ b/common/spl/spl.c
@@ -321,7 +321,7 @@
 		spl_image->fdt_addr = (void *)dt_data;
 
 		if (spl_image->os == IH_OS_U_BOOT) {
-			/* HACK: U-boot expects FDT at a specific address */
+			/* HACK: U-Boot expects FDT at a specific address */
 			fdt_hack = spl_image->load_addr + spl_image->size;
 			fdt_hack = (fdt_hack + 3) & ~3;
 			debug("Relocating FDT to %p\n", spl_image->fdt_addr);