pulpino soc has custom-extended riscv ISA that is accounted
for if CONFIG_RISCV_GENERIC_TOOLCHAIN is not set.
(ex: bit manipulation asm opcodes)
Change-Id: I4dafc4ebc2fedcc4eb6a3dedd0412816afea6004
Signed-off-by: Jean-Paul Etienne <fractalclone@gmail.com>