dm: fpga: Introduce new uclass

For future DM based FPGA drivers and for now to have a meaningful
logging class for old FPGA drivers.

Suggested-by: Michal Simek <michal.simek@amd.com>
Suggested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Alexander Dahl <post@lespocky.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Link: https://lore.kernel.org/r/20220930120430.42307-2-post@lespocky.de
Signed-off-by: Michal Simek <michal.simek@amd.com>

test/dm/Makefile

@@ -47,6 +47,7 @@ ifneq ($(CONFIG_EFI_PARTITION),)
 obj-$(CONFIG_FASTBOOT_FLASH_MMC) += fastboot.o
 endif
 obj-$(CONFIG_FIRMWARE) += firmware.o
+obj-$(CONFIG_DM_FPGA) += fpga.o
 obj-$(CONFIG_DM_HWSPINLOCK) += hwspinlock.o
 obj-$(CONFIG_DM_I2C) += i2c.o
 obj-$(CONFIG_SOUND) += i2s.o