[riscv] Fix ambiguous .md attribute uses

[riscv] Fix ambiguous .md attribute uses

This patch is part of a series that fixes ambiguous attribute
uses in .md files, i.e. cases in which attributes didn't use
<ITER:ATTR> to specify an iterator, and in which <ATTR> could
have different values depending on the iterator chosen.

No behavioural change -- produces the same code as before.

2019-07-08  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/riscv/pic.md (*local_pic_load_s<mode>)
	(*local_pic_load_u<mode>): Explicitly specify the mode iterator
	referenced by <mode>, giving...
	(*local_pic_load_s<SUBX:mode>, *local_pic_load_u<SUBX:mode>): ...these.
	* config/riscv/riscv.md (*sge<u>_<X:mode><GPR:mode>)
	(*slt<u>_<X:mode><GPR:mode>, *sle<u>_<X:mode><GPR:mode>): Explicitly
	use <X:MODE> for the mode attribute.

From-SVN: r273191