Make sure only one udelay function is available

The Agesa wrapper and UDELAY_TIMER2 define their own timer functions,
so don't shove in UDELAY_IO

Change-Id: Ibe3345e825e0c074d5f531dba1198cd6e7b0a42d
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/1864
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/cpu/amd/agesa/Kconfig

@@ -29,6 +29,10 @@ config CPU_AMD_AGESA
 
 if CPU_AMD_AGESA
 
+config UDELAY_IO
+	bool
+	default n
+
 config XIP_ROM_SIZE
 	hex
 	default 0x100000

src/cpu/x86/Kconfig

@@ -4,7 +4,7 @@ config SERIAL_CPU_INIT
 
 config UDELAY_IO
 	bool
-	default y if !UDELAY_LAPIC && !UDELAY_TSC
+	default y if !UDELAY_LAPIC && !UDELAY_TSC && !UDELAY_TIMER2
 	default n
 
 config UDELAY_LAPIC