Remove the executable bit from examples’ Makefiles

The normal way to invoke a Makefile is to run `make`, not to run the
Makefile directly.  Besides they would be missing a shebang anyway.

diff --git a/examples/graphics/bitmap/24bit-color/Makefile b/examples/graphics/bitmap/24bit-color/Makefile
old mode 100755 (executable)
new mode 100644 (file)

diff --git a/examples/graphics/printing/both-screen-text/Makefile b/examples/graphics/printing/both-screen-text/Makefile
old mode 100755 (executable)
new mode 100644 (file)

diff --git a/examples/graphics/printing/colored-text/Makefile b/examples/graphics/printing/colored-text/Makefile
old mode 100755 (executable)
new mode 100644 (file)

diff --git a/examples/graphics/printing/hello-world/Makefile b/examples/graphics/printing/hello-world/Makefile
old mode 100755 (executable)
new mode 100644 (file)

diff --git a/examples/graphics/printing/multiple-windows-text/Makefile b/examples/graphics/printing/multiple-windows-text/Makefile
old mode 100755 (executable)
new mode 100644 (file)

diff --git a/examples/input/read-controls/Makefile b/examples/input/read-controls/Makefile
old mode 100755 (executable)
new mode 100644 (file)

diff --git a/examples/input/touch-screen/Makefile b/examples/input/touch-screen/Makefile
old mode 100755 (executable)
new mode 100644 (file)

diff --git a/examples/time/rtc/Makefile b/examples/time/rtc/Makefile
old mode 100755 (executable)
new mode 100644 (file)