ACPI: docs: enumeration: Fix a few typos and wording mistakes

"sturct" -> "struct"
"similar than with" -> "similar to"
Missing comma, "it" and "to"

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>