mx53loco: Call PMIC related functions from board_late_init()

Since commit c7336815 (pmic: Extend PMIC framework to support multiple instances
of PMIC devices) mx53loco fails to allocate the memory for PMIC:

U-Boot 2013.01-rc2-dirty (Dec 20 2012 - 15:55:01)

Board: MX53 LOCO
I2C:   ready
DRAM:  1 GiB
pmic_alloc: No available memory for allocation!
pmic_init: POWER allocation error!
CPU:   Freescale i.MX53 family rev2.0 at 800 MHz
Reset cause: POR
MMC:   FSL_SDHC: 0, FSL_SDHC: 1

Calling the PMIC related functions at a later stage, ie, from board_late_init()
fixes the issue.

Reported-by: Robert Nelson <robertcnelson@gmail.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Stefano Babic <sbabic@denx.de>