binman: fix a few typos in documentation

This fixes four small typos in the README file.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>
Cc: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/README b/tools/binman/README
index cb34171..9d9d183 100644
--- a/tools/binman/README
+++ b/tools/binman/README
@@ -130,9 +130,9 @@
 
 Binman considers the output files created by mkimage to be binary blobs
 which it can place in an image. Binman does not replace the mkimage tool or
-this purpose. It would be possible in some situtions to create a new entry
+this purpose. It would be possible in some situations to create a new entry
 type for the images in mkimage, but this would not add functionality. It
-seems better to use the mkiamge tool to generate binaries and avoid blurring
+seems better to use the mkimage tool to generate binaries and avoid blurring
 the boundaries between building input files (mkimage) and packaging then
 into a final image (binman).
 
@@ -169,7 +169,7 @@
 In most cases x86 images have a lot of binary blobs, 'black-box' code
 provided by Intel which must be run for the platform to work. Typically
 these blobs are not relocatable and must be placed at fixed areas in the
-firmare image.
+firmware image.
 
 Currently this is handled by ifdtool, which places microcode, FSP, MRC, VGA
 BIOS, reference code and Intel ME binaries into a u-boot.rom file.
@@ -406,7 +406,7 @@
 different name for each and specifying the type with the 'type' attribute.
 
 
-Sections and hiearchical images
+Sections and hierachical images
 -------------------------------
 
 Sometimes it is convenient to split an image into several pieces, each of which