staging: spi: mt7621: Remove superfluous pre-declaration of struct mt7621_spi

This patch removes the superfluous pre-declaration of struct mt7621_spi.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Mark Brown <broonie@kernel.org>
Cc: NeilBrown <neil@brown.name>
Cc: Sankalp Negi <sankalpnegi2310@gmail.com>
Cc: Chuanhong Guo <gch981213@gmail.com>
Cc: John Crispin <john@phrozen.org>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/mt7621-spi/spi-mt7621.c

@@ -51,8 +51,6 @@
 #define MT7621_CPOL		BIT(4)
 #define MT7621_LSB_FIRST	BIT(3)
 
-struct mt7621_spi;
-
 struct mt7621_spi {
 	struct spi_master	*master;
 	void __iomem		*base;