With commit 5def51b0 (ARM: 7211/1: smp_twd: get the rate from a clock)
hitting mainline, if we do not have a twd_clk for lookup, we will see
the following error message in boot log.

 smp_twd: clock not found: -2

Actually we should add this clock regardless of the error message,
so that we can:

 * Avoid the local timer calibrating at boot time
 * Make the local timer cpufreq aware on imx6q
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

The restart support was missed from the initial imx6q submission.
The mxc_restart() does not work for imx6q.  Instead, this patch adds
the restart for imx6q.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

map_io is the only place to call iotable_init.
Signed-off-by: NRichard Zhao <richard.zhao@linaro.org>
[shawn.guo: rename imx_clock_map_io() to imx6q_clock_map_io()]
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

The following error is seen in some case when mounting rootfs from
SD/MMC cards.

  Waiting for root device /dev/mmcblk0p1...
  mmc1: host does not support reading read-only switch. assuming write-enable.
  mmc1: new high speed SDHC card at address b368
  mmcblk0: mmc1:b368 SDC   3.74 GiB
   mmcblk0: p1
  mmc1: Timeout waiting for hardware interrupt.
  mmcblk0: error -110 transferring data, sector 3678224, nr 40, cmd response 0x900, card status 0xc00
  end_request: I/O error, dev mmcblk0, sector 3678225
  Buffer I/O error on device mmcblk0p1, logical block 458754
  lost page write due to I/O error on mmcblk0p1

This patch fixes the problem by lowering the usdhc clock and correcting
watermark configuration.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Cc: Chris Ball <cjb@laptop.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>

It adds a number of core drivers support for imx6q, including clock,
General Power Controller (gpc), Multi Mode DDR Controller(mmdc) and
System Reset Controller (src).
Signed-off-by: NRanjani Vaidyanathan <ra5478@freescale.com>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>