ARM: at91: Remove poweroff code

Now that all the SoC have been converted to use the new poweroff driver, we can
remove the poweroff code defined in mach-at91.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

arch/arm/mach-at91/setup.c

@@ -322,17 +322,11 @@ void __init at91_map_io(void)
 
 void __iomem *at91_shdwc_base = NULL;
 
-static void at91sam9_poweroff(void)
-{
-	at91_shdwc_write(AT91_SHDW_CR, AT91_SHDW_KEY | AT91_SHDW_SHDW);
-}
-
 void __init at91_ioremap_shdwc(u32 base_addr)
 {
 	at91_shdwc_base = ioremap(base_addr, 16);
 	if (!at91_shdwc_base)
 		panic(pr_fmt("Impossible to ioremap at91_shdwc_base\n"));
-	pm_power_off = at91sam9_poweroff;
 }
 
 void __iomem *at91_rstc_base;