indent: Add new recipe

Indent is a GNU program for beautifying C code, so that it is easier
to read. Indent can also convert from one C writing style to a different
one. Indent understands correct C syntax and tries to handle incorrect C
syntax.

Signed-off-by: Qian Lei <qianl.fnst@cn.fujitsu.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>