Function uacpi_table_find_by_signature

Helpers for finding tables.

for find_by_signature: 'signature' is an array of 4 characters, a null terminator is not necessary and can be omitted (especially useful for non-C language bindings) 'out_table' is a pointer to a caller allocated uacpi_table structure that receives the table pointer & its internal index in case the call was successful. NOTE: The returned table's reference count is incremented by 1, which keeps its mapping alive forever unless uacpi_table_unref() is called for this table later on. Calling uacpi_table_find_next_with_same_signature() on a table also drops its reference count by 1, so if you want to keep it mapped you must manually call uacpi_table_ref() beforehand.