rpi-mkimage: install to bindir instead of libexecdir

On fido and earlier branches, ${libexecdir} depends on ${BPN} so it
is not a good choice as ${libexecdir} is different depending on the
recipe name.

For example, rpi-mkimage would install mkknlimg to:
  [...]/sysroots/x86_64-linux/usr/lib/rpi-mkimage
but linux-raspberrypi would look for mkknlimg in the path:
  [...]/sysroots/x86_64-linux/usr/lib/linux-raspberrypi

To resolve this, we use ${bindir} instead as it doesn't depend on
${BPN} in fido and earlier branches as well as in the master branch.

Signed-off-by: Jonathan Liu <net147@gmail.com>

recipes-bsp/rpi-mkimage/rpi-mkimage_git.bb

@@ -15,8 +15,8 @@ SRC_URI = " \
 S = "${WORKDIR}/git"
 
 do_install () {
-    install -d ${D}${libexecdir}
-    install -t ${D}${libexecdir} mkimage/*
+    install -d ${D}${bindir}
+    install -t ${D}${bindir} mkimage/*
 }
 
 BBCLASSEXTEND = "native"