elog: Do not attempt to init SPI

This severs a dependency the eventlog code has on initializing
chipset/SoC SPI controller. Currently elog_init() calls spi_init()
as a catch-all. This worked for x86 since the SPI controller is only
used for one thing on existing platforms. As we add eventlogging
support to non-x86 platforms we need to consider the more generalized
case where the assumptions about how SPI works on x86 are no longer
valid.

BUG=none
BRANCH=none
Signed-off-by: David Hendricks <dhendrix@chromium.org>
TEST=built and booted on Link, Beltino and Rambi. See below for
"mosys eventlog list" output on Link showing boot and suspend/resume
events (including lid close/open) added successfully.

localhost ~ # mosys eventlog list
0 | 2014-04-14 13:52:44 | Log area cleared | 4096
1 | 2014-04-14 13:52:44 | System boot | 50
2 | 2014-04-14 13:52:44 | EC Event | Power Button
3 | 2014-04-14 13:52:44 | SUS Power Fail
4 | 2014-04-14 13:52:44 | System Reset
5 | 2014-04-14 13:52:44 | ACPI Wake | S5
6 | 2014-04-14 13:53:25 | ACPI Enter | S3
7 | 2014-04-14 13:53:35 | ACPI Wake | S3
8 | 2014-04-14 13:53:35 | Wake Source | RTC Alarm | 0
9 | 2014-04-14 13:53:49 | ACPI Enter | S3
10 | 2014-04-14 13:54:00 | EC Event | Lid Open
11 | 2014-04-14 13:54:00 | ACPI Wake | S3
12 | 2014-04-14 13:54:00 | Wake Source | GPIO | 15

Original-Change-Id: I26e25c0a856f7b8db5ab6b8e7e1acae291d2eadc
Original-Reviewed-on: https://chromium-review.googlesource.com/194526
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
Original-Commit-Queue: David Hendricks <dhendrix@chromium.org>
Original-Tested-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 2971d20b6ebdd9803b05ccbbaeefe1bde1a21af4)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: Ia5f2913fd8e4fee6e741e6d1e39d32bb86525cb3
Reviewed-on: http://review.coreboot.org/7831
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/drivers/elog/elog.c b/src/drivers/elog/elog.c
index 059b089..94af16e 100644
--- a/src/drivers/elog/elog.c
+++ b/src/drivers/elog/elog.c
@@ -546,8 +546,7 @@
 
 	elog_debug("elog_init()\n");
 
-	/* Prepare SPI */
-	spi_init();
+	/* Probe SPI chip. SPI controller must already be initialized. */
 	elog_spi = spi_flash_probe(CONFIG_BOOT_MEDIA_SPI_BUS, 0);
 	if (!elog_spi) {
 		printk(BIOS_ERR, "ELOG: Unable to find SPI flash\n");