Revert "Input: olpc_apsp - enable the SP clock"

Turns out this is not such a great idea. Once the SP clock is disabled,
it's not sufficient to just enable in order to bring the SP core back up.

It seems that the kernel has no business managing this clock. Just let
the firmware keep it enabled.

This reverts commit ed22cee91a88c47e564478b012fdbcb079653499.

Link: https://lore.kernel.org/lkml/[e-mail]/
Signed-off-by: Lubomir Rintel <[e-mail]>
Acked-by: Dmitry Torokhov <[e-mail]>
Signed-off-by: Stephen Boyd <[e-mail]>

Documentation/devicetree/bindings/serio/olpc,ap-sp.txt

···
 - compatible : "olpc,ap-sp"
 - reg : base address and length of SoC's WTM registers
 - interrupts : SP-AP interrupt
-- clocks : phandle + clock-specifier for the clock that drives the WTM
-- clock-names:  should be "sp"
 
 Example:
 	ap-sp@d4290000 {
 		compatible = "olpc,ap-sp";
 		reg = <0xd4290000 0x1000>;
 		interrupts = <40>;
-		clocks = <&soc_clocks MMP2_CLK_SP>;
-		clock-names = "sp";
 	}

drivers/input/serio/olpc_apsp.c

···
 #include <linux/of.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
-#include <linux/clk.h>
 
 /*
  * The OLPC XO-1.75 and XO-4 laptops do not have a hardware PS/2 controller.
···
 	struct serio *kbio;
 	struct serio *padio;
 	void __iomem *base;
-	struct clk *clk;
 	int open_count;
 	int irq;
 };
···
 	struct olpc_apsp *priv = port->port_data;
 	unsigned int tmp;
 	unsigned long l;
-	int error;
 
 	if (priv->open_count++ == 0) {
-		error = clk_prepare_enable(priv->clk);
-		if (error)
-			return error;
-
 		l = readl(priv->base + COMMAND_FIFO_STATUS);
 		if (!(l & CMD_STS_MASK)) {
 			dev_err(priv->dev, "SP cannot accept commands.\n");
-			clk_disable_unprepare(priv->clk);
 			return -EIO;
 		}
 
···
 		/* Disable interrupt 0 */
 		tmp = readl(priv->base + PJ_INTERRUPT_MASK);
 		writel(tmp | INT_0, priv->base + PJ_INTERRUPT_MASK);
-
-		clk_disable_unprepare(priv->clk);
 	}
 }
 
···
 	priv->irq = platform_get_irq(pdev, 0);
 	if (priv->irq < 0)
 		return priv->irq;
-
-	priv->clk = devm_clk_get(&pdev->dev, "sp");
-	if (IS_ERR(priv->clk))
-		return PTR_ERR(priv->clk);
 
 	/* KEYBOARD */
 	kb_serio = kzalloc(sizeof(struct serio), GFP_KERNEL);