arch/non-x86: Flip HAVE_MONOTONIC_TIMER default

Also remove allwinner/a10 dummy monotonic_timer
implementation.

Change-Id: I9dfa9b92dc63375465e3bb87b73eeefad601c810
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34112
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/Kconfig

@@ -501,14 +501,20 @@ config HAVE_ROMSTAGE_MICROCODE_CBFS_SPINLOCK
 	bool
 	default n
 
-config HAVE_MONOTONIC_TIMER
+config NO_MONOTONIC_TIMER
 	def_bool n
+
+config HAVE_MONOTONIC_TIMER
+	bool
+	depends on !NO_MONOTONIC_TIMER
+	default y if !ARCH_X86
 	help
 	 The board/chipset provides a monotonic timer.
 
 config GENERIC_UDELAY
-	def_bool n
+	bool
 	depends on HAVE_MONOTONIC_TIMER
+	default y if !ARCH_X86
 	help
 	 The board/chipset uses a generic udelay function utilizing the
 	 monotonic timer.