ectool: add query function to ectool

`ectool -q` - Query the EC IRQ byte.
Should return 0x00 otherwise the IRQ handler is usally broken or disabled.

Tested-on: Lenovo X201t

Change-Id: I0b8c2dbcf38d2eab89d0fbea05795759c4517f6d
Signed-off-by: Alexander Couzens <lynxis@fe80.eu>
Reviewed-on: http://review.coreboot.org/8382
Tested-by: build bot (Jenkins)
Reviewed-by: Nicolas Reinecke <nr@das-labor.org>
Reviewed-by: Peter Stuge <peter@stuge.se>

util/ectool/ec.h

@@ -50,4 +50,5 @@ int ec_write(uint8_t addr, uint8_t data);
 uint8_t ec_ext_read(uint16_t addr);
 int ec_ext_write(uint16_t addr, uint8_t data);
 uint8_t ec_idx_read(uint16_t addr);
+uint8_t ec_query(void);
 #endif