MIPS: pic32: treat port as signed integer

stable inclusion
from stable-v5.10.157
commit 836bbdfcf8ef4b9b8a10c1f6fee3cff2b72bedc7
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7MU59

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=836bbdfcf8ef4b9b8a10c1f6fee3cff2b72bedc7



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[ Upstream commit 64806090 ]

get_port_from_cmdline() returns an int, yet is assigned to a char, which
is wrong in its own right, but also, with char becoming unsigned, this
poses problems, because -1 is used as an error value. Further
complicating things, fw_init_early_console() is only ever called with a
-1 argument. Fix this up by removing the unused argument from
fw_init_early_console() and treating port as a proper signed integer.

Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>