spi/pl022: disable port when unused

Commit ffbbdd2132
"spi: create a message queueing infrastructure"
Accidentally deleted the logic to disable the port
when unused leading to higher power consumption.
Fix this up.

Cc: stable@kernel.org
Cc: Vinit Shenoy <vinit.shenoy@st.com>
Signed-off-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/spi/spi-pl022.c

@@ -489,6 +489,11 @@ static void giveback(struct pl022 *pl022)
 	pl022->cur_transfer = NULL;
 	pl022->cur_chip = NULL;
 	spi_finalize_current_message(pl022->master);
+
+	/* disable the SPI/SSP operation */
+	writew((readw(SSP_CR1(pl022->virtbase)) &
+		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
+
 }
 
 /**