arm: socfpga: reset: Repair bridge reset handling

arm: socfpga: reset: Repair bridge reset handling

The current bridge reset code, which de-asserted the bridge reset,
was activelly polling whether the FPGA is programmed and ready and
in case it was (!), the code called hang(). This makes no sense at
all. Repair it such that the code instead checks whether the FPGA
is programmed, but without any polling involved, and only if it is
programmed, it de-asserts the reset.

Signed-off-by: Marek Vasut <marex@denx.de>