[binutils-gdb] gdb: Add riscv to list of architectures with a save_reggroup

[sergiodj+buildbot at sergiodj dot net]

*** TEST RESULTS FOR COMMIT ea005f31ca7a823680c70a75ae073bee52487859 ***

Author: Andrew Burgess <andrew.burgess@embecosm.com>
Branch: master
Commit: ea005f31ca7a823680c70a75ae073bee52487859

gdb: Add riscv to list of architectures with a save_reggroup

The regcache cooked_read test needs to know which architectures have a
save_reggroup, riscv does and needs adding to the list.

gdb/ChangeLog:

	* regcache.c (cooked_read_test): Add riscv to the list of
	architectures that have a save_reggroup.