fpga: Fix debug message compilation error

CONFIG_FPGA in past was a bitfield where bits
were use for vendor identification.

This fix should be the part of this commit:
"Improve configuration of FPGA subsystem"
(sha1: 0133502e39ff89b67c26cb4015e0e7e8d9571184)

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Tom Rini <trini@ti.com>

drivers/fpga/fpga.c

@@ -145,7 +145,7 @@ void fpga_init(void)
 	next_desc = 0;
 	memset(desc_table, 0, sizeof(desc_table));
 
-	debug("%s: CONFIG_FPGA = 0x%x\n", __func__, CONFIG_FPGA);
+	debug("%s\n", __func__);
 }
 
 /*