All slots in sysrq_key_table[] are either used, reserved or at least
commented with their intended use. This patch adds capital letter versions
available, which means adding 26 more entries.

For already existing SysRq operations the user presses Alt-SysRq-<key>, and
for the newly added ones Alt-Shift-SysRq-<key>.
Signed-off-by: NAndrzej Pietrasiewicz <andrzej.p@collabora.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20200818112825.6445-2-andrzej.p@collabora.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>