cpupower-idle-info.1: fix short option names

cpupower-idle-info.1: fix short option names

The cpupower-idle-info(1) man page describes '-f' as the short form of the
'--silent' option and '-e' as the short form of the '--proc' option.
But they are not correct:

$ cpupower idle-info -f
idle-info: invalid option -- 'f'
invalid or unknown argument
$ cpupower idle-info -e
idle-info: invalid option -- 'e'
invalid or unknown argument

The short form of '--silent' is actually '-s' and the short form of
'--proc' is actually '-o':

cpuidle-info.c:
	{"silent", no_argument, NULL, 's'},
	{"proc", no_argument, NULL, 'o'},

Signed-off-by: Roberto Ricci <io@r-ricci.it>
Link: https://lore.kernel.org/r/20260324223921.14317-2-io@r-ricci.it
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>