rockchip: rk3399: configure emmc clk

Select aclk_emmc and clk_emmc source from GPLL, and both to 198MHz,
that is GPLL(594MHz) divided by 3.

BRANCH=none
BUG=chrome-os-partner:51537
TEST=boot kevin rev1 to chromeos prompt from both emmc and sdcard
TEST=LoadKernel faster, more than twice as I measured manually.

Change-Id: I2580c43b8c79049c3fe16bbf60bfa1a8e0559948
Signed-off-by: Martin Roth <martinroth@google.com>
Original-Commit-Id: 5fd37b66dcce77354e1cafab0d6e806d832c08d2
Original-Change-Id: Id22815b302af3204e0e5537af99c1577b09b0877
Original-Signed-off-by: Lin Huang <hl@rock-chips.com>
Original-Signed-off-by: Shunqian Zheng <zhengsq@rock-chips.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/339152
Original-Commit-Ready: Vadim Bendebury <vbendeb@chromium.org>
Original-Tested-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://review.coreboot.org/14855
Tested-by: build bot (Jenkins)
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
diff --git a/src/mainboard/google/gru/mainboard.c b/src/mainboard/google/gru/mainboard.c
index 4a5ed4f..6d2b4f4 100644
--- a/src/mainboard/google/gru/mainboard.c
+++ b/src/mainboard/google/gru/mainboard.c
@@ -20,6 +20,20 @@
 #include <soc/clock.h>
 #include <soc/grf.h>
 
+static void configure_emmc(void)
+{
+	/* Host controller does not support programmable clock generator.
+	 * If we don't do this setting, when we use phy to control the
+	 * emmc clock(when clock exceed 50MHz), it will get wrong clock.
+	 *
+	 * Refer to TRM V0.3 Part 1 Chapter 15 PAGE 782 for this register.
+	 * Please search "_CON11[7:0]" to locate register description.
+	 */
+	write32(&rk3399_grf->emmccore_con[11], RK_CLRSETBITS(0xff, 0));
+
+	rkclk_configure_emmc();
+}
+
 static void configure_sdmmc(void)
 {
 	gpio_output(GPIO(4, D, 5), 1);  /* SDMMC_PWR_EN */
@@ -72,6 +86,7 @@
 static void mainboard_init(device_t dev)
 {
 	configure_sdmmc();
+	configure_emmc();
 }
 
 static void mainboard_enable(device_t dev)