target-mips: fix semihosting for microMIPS R6 In semihosting mode the SDBBP 1 instructions should trigger UHI syscall, but in QEMU this does not happen for recently added microMIPS R6. Consequently bare metal microMIPS R6 programs supporting UHI will not run. Signed-off-by: Leon Alrae <leon.alrae@imgtec.com> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>