arm: am437x: cm-t43: set MPU and CORE voltages on boot

arm: am437x: cm-t43: set MPU and CORE voltages on boot

During boot, U-Boot raises the CPU frequency but the CORE and MPU regulators
are not updated. This is not a problem in cold boot since the default values
that the pmic outputs are correct, but if Linux were to switch the module to a
low power OPP, the new voltage values will be retained after a reboot and the
module will likely hang once U-Boot raises the CPU frequency back up.

Set both CORE and MPU regulators to to 1.1V on boot.

Cc: Tom Rini <trini@konsulko.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Reviewed-by: Tom Rini <trini@konsulko.com>