[ARM] Fix qsat for armv5te/armv6 + thumb-mode

This is a Thumb1 target, so will not have qsat instructions available. There
was a mismatch between hasBaseDSP and the instruction patterns when +dsp was
present, which is set by clang (but maybe shouldn't be). The target being
thumb1-only should override that, implying that it does not have any qadds.

Fixes #62273