libpayload: Replace majority of timer drivers with a generic one

Currently every non-x86 platform supported by libpayload needs to
provide its own timer driver. Most of the ones we have accumulated there
look almost identical: For the frequency, return a preset constant. For
the value, read a 32-bit register, possibly read another 32-bit register
and shift+OR it with the previous one, then return that.

Let's replace this with a single .c file that can easily handle all of
those cases. Menuconfig convenience can still be maintained by providing
several presets that select different defaults for the driver's
configuration options (register address(es) and frequency).

Removes an "enabled" check from Samsung MCT driver since coreboot always
unconditionally enables that timer anyway.

CQ-DEPEND=CL:344809
BRANCH=None
BUG=None
TEST=Booted Oak and Veyron, observed how dev-mode delay was still ~30s

Change-Id: I61cb7d2ffd4902aa841c57f9afa9cd991f770acd
Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Commit-Id: a036af6
Original-Change-Id: I9784e7c6aa5abd6d92478ea7ec1cf42c9a437546
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/347749
Reviewed-on: https://review.coreboot.org/17023
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
diff --git a/payloads/libpayload/drivers/Makefile.inc b/payloads/libpayload/drivers/Makefile.inc
index 899c5d2..1fa0ec3 100644
--- a/payloads/libpayload/drivers/Makefile.inc
+++ b/payloads/libpayload/drivers/Makefile.inc
@@ -46,16 +46,11 @@
 libc-$(CONFIG_LP_NVRAM) += options.c
 
 # Timer drivers
-libc-$(CONFIG_LP_TIMER_MTK) += timer/mtk_timer.c
-libc-$(CONFIG_LP_TIMER_MCT) += timer/mct.c
+ifneq ($(CONFIG_LP_TIMER_GENERIC_HZ),0)
+libc-y += timer/generic.c
+endif
 libc-$(CONFIG_LP_TIMER_RDTSC) += timer/rdtsc.c
-libc-$(CONFIG_LP_TIMER_TEGRA_1US) += timer/tegra_1us.c
-libc-$(CONFIG_LP_TIMER_IPQ806X) += timer/ipq806x.c
-libc-$(CONFIG_LP_TIMER_IPQ40XX) += timer/ipq40xx.c
-libc-$(CONFIG_LP_TIMER_RK) += timer/rktimer.c
-libc-$(CONFIG_LP_TIMER_BG4CD) += timer/bg4cd.c
 libc-$(CONFIG_LP_TIMER_IMG_PISTACHIO) += timer/img_pistachio.c
-libc-$(CONFIG_LP_TIMER_CYGNUS) += timer/cygnus.c
 libc-$(CONFIG_LP_TIMER_ARMADA38X) += timer/armada38x.c
 libc-$(CONFIG_LP_TIMER_MVMAP2315) += timer/mvmap2315.c