event: Convert existing spy records to simple

Very few of the existing event-spy records use the arguments they are
passed. Update them to use a simple spy instead, to simplify the code.

Where an adaptor function is currently used, remove it where possible.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/mach-imx/imx8/cpu.c b/arch/arm/mach-imx/imx8/cpu.c
index c623570..39ac0bc 100644
--- a/arch/arm/mach-imx/imx8/cpu.c
+++ b/arch/arm/mach-imx/imx8/cpu.c
@@ -69,7 +69,7 @@
 	return 0;
 }
 
-static int imx8_init_mu(void *ctx, struct event *event)
+static int imx8_init_mu(void)
 {
 	struct udevice *devp;
 	int node, ret;
@@ -91,7 +91,7 @@
 
 	return 0;
 }
-EVENT_SPY(EVT_DM_POST_INIT_F, imx8_init_mu);
+EVENT_SPY_SIMPLE(EVT_DM_POST_INIT_F, imx8_init_mu);
 
 #if defined(CONFIG_ARCH_MISC_INIT)
 int arch_misc_init(void)