mfd: cros_ec_spi: Warnings fix

To silent those:

 CC [M]  drivers/mfd/cros_ec_spi.o
drivers/mfd/cros_ec_spi.c: In function ‘cros_ec_spi_receive_response’:
drivers/mfd/cros_ec_spi.c:123:5: warning: format ‘%d’ expects argument of type
‘int’, but argument 4 has type ‘long int’ [-Wformat]
drivers/mfd/cros_ec_spi.c:157:3: warning: format ‘%d’ expects argument of type
‘int’, but argument 6 has type ‘long int’ [-Wformat]
drivers/mfd/cros_ec_spi.c:181:2: warning: format ‘%d’ expects argument of type
‘int’, but argument 4 has type ‘long int’ [-Wformat]

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>