greybus: Remove extra blank lines

This patch removes few blank lines across the repository at places where
two blank lines were present together or when a blank line is present at
the start or end of a routine.

Note that this doesn't remove most of them from greybus_protocols.h as
they were added on purpose.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>