CORE-V: Event Load Builtin Update

    Updated __builtin_riscv_cv_elw_elw to take in a void pointer as an arguement
    to match the CORE-V builtin specifcation.

    * gcc/config/riscv/corev.def: Changed builtin argument to take a void
      pointer.
    * gcc/testsuite/gcc.target/riscv/cv-elw-elw-compile-1.c: Updated
      builtin test to take in a void pointer.

Signed-off-by: Nandni Jamnadas <nandni.jamnadas@embecosm.com>