Blackfin arch: Fix BUG - kernel fails to build in pm.c when allow wakeup fromi standby by GPIO

This feature is not available on BF54x.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

arch/blackfin/Kconfig

@@ -1129,6 +1129,7 @@ endchoice
 
 config PM_WAKEUP_BY_GPIO
 	bool "Allow Wakeup from Standby by GPIO"
+	depends on PM && !BF54x
 
 config PM_WAKEUP_GPIO_NUMBER
 	int "GPIO number"