ramips: remove broken and bogus spinlock in the SPI driver

Based on patch by Neil Brown

Signed-off-by: Felix Fietkau <nbd@nbd.name>

target/linux/ramips/patches-4.14/0043-spi-add-mt7621-support.patch

@@ -38,7 +38,7 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
  obj-$(CONFIG_SPI_OC_TINY)		+= spi-oc-tiny.o
 --- /dev/null
 +++ b/drivers/spi/spi-mt7621.c
-@@ -0,0 +1,491 @@
+@@ -0,0 +1,488 @@
 +/*
 + * spi-mt7621.c -- MediaTek MT7621 SPI controller driver
 + *
@@ -106,7 +106,6 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +	unsigned int		sys_freq;
 +	unsigned int		speed;
 +	struct clk		*clk;
-+	spinlock_t		lock;
 +
 +	struct mt7621_spi_ops	*ops;
 +};
@@ -438,7 +437,6 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +	const struct of_device_id *match;
 +	struct spi_master *master;
 +	struct mt7621_spi *rs;
-+	unsigned long flags;
 +	void __iomem *base;
 +	struct resource *r;
 +	int status = 0;
@@ -490,7 +488,6 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +	rs->sys_freq = clk_get_rate(rs->clk);
 +	rs->ops = ops;
 +	dev_info(&pdev->dev, "sys_freq: %u\n", rs->sys_freq);
-+	spin_lock_irqsave(&rs->lock, flags);
 +
 +	device_reset(&pdev->dev);
 +