spi/pl022: fix build warnings

The driver build complains with newer compilers unless you
initialize this struct properly.

Reviewed-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/spi/spi-pl022.c

@@ -1886,7 +1886,7 @@ static int pl022_setup(struct spi_device *spi)
 {
 	struct pl022_config_chip const *chip_info;
 	struct chip_data *chip;
-	struct ssp_clock_params clk_freq = {0, };
+	struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
 	int status = 0;
 	struct pl022 *pl022 = spi_master_get_devdata(spi->master);
 	unsigned int bits = spi->bits_per_word;