lib: sbi: Fixup tinst for exceptions in sbi_misaligned_*()

If there is an exception while emulating a misaligned load/store, fixup
uptrap.tinst before redirecting. Otherwise, HS-mode software may receive
an htinst describing the lbu/sb instruction that faulted during
emulation[1].

[1]: https://github.com/riscv-software-src/opensbi/issues/258



Signed-off-by: dramforever <dramforever@live.com>
Reviewed-by: Anup Patel <anup@brainfault.org>