fpga: Migrate CONFIG_MAX_FPGA_DEVICES to Kconfig

This is always defined to 5, so use that as the default.

Cc: Michal Simek <michal.simek@amd.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Michal Simek <michal.simek@amd.com>

drivers/fpga/fpga.c

@@ -13,11 +13,6 @@
 #include <lattice.h>
 #include <dm/device_compat.h>
 
-/* Local definitions */
-#ifndef CONFIG_MAX_FPGA_DEVICES
-#define CONFIG_MAX_FPGA_DEVICES		5
-#endif
-
 /* Local static data */
 static int next_desc = FPGA_INVALID_DEVICE;
 static fpga_desc desc_table[CONFIG_MAX_FPGA_DEVICES];