spi: xilinx_spi: Add missing prototype for xilinx_qspi_mem_exec_op

Add missing prototype to fix the below sparse warning
warning: no previous prototype for 'xilinx_qspi_mem_exec_op'
[-Wmissing-prototypes]

Signed-off-by: Algapally Santosh Sagar <santoshsagar.algapally@amd.com>
Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@amd.com>
Link: https://lore.kernel.org/r/20230614090359.10809-2-ashok.reddy.soma@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>
1 file changed