Similar to the device parameter functions also make the globalvar
functions more consistent. This also adds support for readonly
globalvars and changes several existing globalvars which should
really be readonly to readonly.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Baltos devices provide a mPCIe slot, whose power is turned off by
default. This patch activates mPCIe slot in barebox, so that for example
GSM modem can be already available in user space.

Also configure external GPIO controller via setting its output pins to
low.

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

EEPROM information is needed in barebox.bin in order to setup MACs and
select appropriate DTB from kernel-fit.itb, so disable this initcall
in MLO.

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

OnRISC Baltos devices are based on a am335x SoC and can be booted
either from MMC or NAND.

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>