clocksource/fsl: Avoid harmless 64-bit warnings

The ftm_clockevent_init passes the value of "~0UL" into a function
that takes a 32-bit argument, which drops the upper 32 bits, as
gcc warns about on ARM64:

clocksource/fsl_ftm_timer.c: In function 'ftm_clockevent_init':
clocksource/fsl_ftm_timer.c:206:13: warning: large integer implicitly truncated to unsigned type [-Woverflow]

This was obviously unintended behavior, and is easily avoided by
using '~0u' as the integer literal, because that is 32-bit wide
on all architectures.

Signed-off-by: Arnd Bergmann <[e-mail]>
Cc: [e-mail]
Cc: Xiubo Li <[e-mail]>
Cc: Shawn Guo <[e-mail]>
Cc: Sascha Hauer <[e-mail]>
Cc: Stefan Agner <[e-mail]>
Cc: Daniel Lezcano <[e-mail]>
Link: http://lkml.kernel.org/r/3990834.xnjhm37Grs@wuerfel
Signed-off-by: Thomas Gleixner <[e-mail]>

drivers/clocksource/fsl_ftm_timer.c

···
 	int err;
 
 	ftm_writel(0x00, priv->clkevt_base + FTM_CNTIN);
-	ftm_writel(~0UL, priv->clkevt_base + FTM_MOD);
+	ftm_writel(~0u, priv->clkevt_base + FTM_MOD);
 
 	ftm_reset_counter(priv->clkevt_base);
 
···
 	int err;
 
 	ftm_writel(0x00, priv->clksrc_base + FTM_CNTIN);
-	ftm_writel(~0UL, priv->clksrc_base + FTM_MOD);
+	ftm_writel(~0u, priv->clksrc_base + FTM_MOD);
 
 	ftm_reset_counter(priv->clksrc_base);