[Bug target/106532] riscv fails to build enabling ZBA/ZBB/ZBC/ZBS by default for 32bit

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106532

--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
So this has been broken since ZBS support was added in r12-4658-g4e1e0d79ecbe87
.
Removing TARGET_64BIT from the check in splittable_const_int_operand fixes this
testcase but I have not done any more testing.