spi: xilinx: Remove unused variable

Warning is:

xilinx_spi.c: In function 'spi_setup_slave':
xilinx_spi.c:81: warning: unused variable 'regs'

Signed-off-by: Stephan Linz <linz@li-pro.net>
CC: Michal Simek <monstr@monstr.eu>

drivers/spi/xilinx_spi.c

@@ -78,7 +78,6 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 				  unsigned int max_hz, unsigned int mode)
 {
 	struct xilinx_spi_slave *xilspi;
-	struct xilinx_spi_reg *regs;
 
 	if (!spi_cs_is_valid(bus, cs)) {
 		printf("XILSPI error: %s: unsupported bus %d / cs %d\n",