Remove executable permissions for text files

In the current state of the repository, meson.build, README.md
and LICENSE files are checked in with executable permissions.
They dont need executable permissions as they are not executables
themselves, so removing the permissions.

Change-Id: Id693bd165ab3a2cf1d3478cd78bd4171bf2a38db
Signed-off-by: Manojkiran Eda <manojkiran.eda@gmail.com>
diff --git a/LICENSE b/LICENSE
old mode 100755
new mode 100644
diff --git a/README.md b/README.md
old mode 100755
new mode 100644
diff --git a/meson.build b/meson.build
old mode 100755
new mode 100644