lib: Rename compiler intrinsic selects to GENERIC_LIB_*

When these are included into arch Kconfig files, maintaining
alphabetical ordering of the selects means these get split up. To allow
for keeping things tidier and alphabetical, rename the selects to
GENERIC_LIB_*

Signed-off-by: Matt Redfearn <matt.redfearn@mips.com>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Antony Pavlov <antonynpavlov@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-riscv@lists.infradead.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/19049/
Signed-off-by: James Hogan <jhogan@kernel.org>