spi: zynq_qspi: Add missing prototype for update_stripe

Add missing prototype to fix the sparse warning,
warning: no previous prototype for 'update_stripe'
[-Wmissing-prototypes].

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com>
Link: https://lore.kernel.org/r/20241016044402.18052-1-venkatesh.abbarapu@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>
diff --git a/drivers/spi/zynq_qspi.c b/drivers/spi/zynq_qspi.c
index f5b3fb5..4aad324 100644
--- a/drivers/spi/zynq_qspi.c
+++ b/drivers/spi/zynq_qspi.c
@@ -734,7 +734,7 @@
 	return 0;
 }
 
-bool update_stripe(const struct spi_mem_op *op)
+static bool update_stripe(const struct spi_mem_op *op)
 {
 	if (op->cmd.opcode == SPINOR_OP_BE_4K ||
 	    op->cmd.opcode == SPINOR_OP_CHIP_ERASE ||