exynos5250/snow: call PMIC's power_init() function

Call the power_init() function. We appear to have forgotten about it
when deprecating lowlevel_init_subsystems(), but it didn't seem to
cause problems until we got to doing more interesting stuff recently.

There are some clean-ups to do from the original code, such as not
attempting to configure I2C from PMIC code, which we'll get around
to in follow-up patches.

(Credit to Gabe for spotting this)

Change-Id: I6a59379e9323277d0b61469de9abe6d651ac5bfb
Signed-off-by: Gabe Black <gabeblack@chromium.org>
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/2699
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/cpu/samsung/exynos5250/Makefile.inc

@@ -17,6 +17,7 @@ romstage-y += pinmux.c  # required by s3c24x0_i2c (exynos5-common) and uart.
 romstage-y += exynos_cache.c
 romstage-y += dmc_common.c
 romstage-y += dmc_init_ddr3.c
+romstage-y += power.c
 romstage-$(CONFIG_EARLY_CONSOLE) += soc.c
 romstage-$(CONFIG_EARLY_CONSOLE) += uart.c