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/arch/Kconfig.nxp b/arch/Kconfig.nxp
index 6e1c44b..e75226b 100644
--- a/arch/Kconfig.nxp
+++ b/arch/Kconfig.nxp
@@ -90,7 +90,7 @@
 	default ""
 	help
 	  Set the key hash for U-Boot here if public/private key pair used to
-	  sign U-boot are different from the SRK hash put in the fuse.  Example
+	  sign U-Boot are different from the SRK hash put in the fuse.  Example
 	  of a key hash is
 	  41066b564c6ffcef40ccbc1e0a5d0d519604000c785d97bbefd25e4d288d1c8b.
 	  Otherwise leave this empty.