ACPI / EC: Remove unused functions and add prototype declaration in internal.h

Adds the prototype declarations of functions acpi_ec_add_query_handler()
and acpi_ec_remove_query_handler() in header file internal.h and removes
unused functions ec_burst_enable() and ec_burst_disable() in ec.c.

This eliminates the following warnings in ec.c:
drivers/acpi/ec.c:393:5: warning: no previous prototype for ‘ec_burst_enable’ [-Wmissing-prototypes]
drivers/acpi/ec.c:402:5: warning: no previous prototype for ‘ec_burst_disable’ [-Wmissing-prototypes]
drivers/acpi/ec.c:531:5: warning: no previous prototype for ‘acpi_ec_add_query_handler’ [-Wmissing-prototypes]
drivers/acpi/ec.c:552:6: warning: no previous prototype for ‘acpi_ec_remove_query_handler’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index a29739c..8ef9787 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -127,12 +127,21 @@
 
 extern struct acpi_ec *first_ec;
 
+/* If we find an EC via the ECDT, we need to keep a ptr to its context */
+/* External interfaces use first EC only, so remember */
+typedef int (*acpi_ec_query_func) (void *data);
+
 int acpi_ec_init(void);
 int acpi_ec_ecdt_probe(void);
 int acpi_boot_ec_enable(void);
 void acpi_ec_block_transactions(void);
 void acpi_ec_unblock_transactions(void);
 void acpi_ec_unblock_transactions_early(void);
+int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
+			      acpi_handle handle, acpi_ec_query_func func,
+			      void *data);
+void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
+
 
 /*--------------------------------------------------------------------------
                                   Suspend/Resume