spi: xtensa-xtfpga: Fix checkpatch issue

Fix the following checkpatch warnings.

  WARNING: Missing a blank line after declarations
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-xtensa-xtfpga.c

@@ -46,6 +46,7 @@ static inline unsigned int xtfpga_spi_read32(const struct xtfpga_spi *spi,
 static inline void xtfpga_spi_wait_busy(struct xtfpga_spi *xspi)
 {
 	unsigned i;
+
 	for (i = 0; xtfpga_spi_read32(xspi, XTFPGA_SPI_BUSY) &&
 	     i < BUSY_WAIT_US; ++i)
 		udelay(1);