pit: setup voltage rails before system clocks

This moves the call to setup_power() before system_clock_init().
This causes the PMIC to set up the voltage rails earlier so that
the CPU clock can be set up at a faster rate (in the follow-up
patch). After system clock init, we re-initialize the PMIC's I2C
bus since the input clock rate will have changed.

Old-Change-Id: Ieb828ac25daad7ee95bfa4823aaaf161028c9c92
Reviewed-on: https://gerrit.chromium.org/gerrit/64744
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Reviewed-by: Ronald G. Minnich <rminnich@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
Commit-Queue: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 6c133a84ef4a32c35577a266905e02af8c2d9278)

pit: save setup_power() status and die later if needed

Since system clock and console initialization now happen after power
setup, we cannot print error messages in setup_power(). This patch
re-factors the code a little bit to save the status of setup_power()
so that if we get an error during setup_power() we will wait until
we can actually print something before dying.

Old-Change-Id: Id7ff477224b104b3c7e221c1d2df460ca9125f3b
Reviewed-on: https://gerrit.chromium.org/gerrit/65009
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Commit-Queue: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 0c89f922b20bc1291ac7ba7b2c22bdce911be7a4)

Squashed two closely related commits.

Change-Id: I3efe29412738959e698c89d26e682536ceabdff8
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6403
Tested-by: build bot (Jenkins)
Reviewed-by: David Hendricks <dhendrix@chromium.org>