MIPS: tplink-mr3020: skip pbl lowlevel init if running from RAM
TP-Link MR3020 has 4 MiB flash boot ROM.
Usually boot ROM is mapped to 0xbfc00000.
However, as AR9331 allows to remap boot ROM to 0xbf000000
it's better to assume that boot ROM starts at 0xbf000000.
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>