stm32mp: stm32prog: fix the content of short help message

Reduce the content of short help message for stm32prog command and
removed the carriage return to fix the display of 'help' command when
this command is activated.

Fixes: 954bd1a923a6 ("stm32mp: add the command stm32prog")
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
1 file changed