include: Replace #csr with __ASM_STR(csr) in csr_xyz() macros

We replace #csr with __ASM_STR(csr) in all csr_xyz() macros
so that we can pass CSR number instead of CSR name when GCC
is not aware of CSR name.

Signed-off-by: Anup Patel <anup.patel@wdc.com>