kstrtox: add support for enabled and disabled in kstrtobool()

In some places in the kernel there is a design pattern for sysfs
attributes to use kstrtobool() in store() and str_enabled_disabled() in
show().

This is counterintuitive to interact with because kstrtobool() takes
on/off but str_enabled_disabled() shows enabled/disabled. Some of those
sysfs uses could switch to str_on_off() but for some attributes
enabled/disabled really makes more sense.

Add support for kstrtobool() to accept enabled/disabled.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Mario Limonciello <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

lib/kstrtox.c

···
 		return -EINVAL;
 
 	switch (s[0]) {
+	case 'e':
+	case 'E':
 	case 'y':
 	case 'Y':
 	case 't':
···
 	case '1':
 		*res = true;
 		return 0;
+	case 'd':
+	case 'D':
 	case 'n':
 	case 'N':
 	case 'f':