nv30: remove unused nvfx_fp_memcpy() function and comment nv40_fp_bra()
nv30: remove unused nvfx_fp_memcpy() function and comment nv40_fp_bra()

The nv40_fp_bra() function in the same file is also unused but this is
the only place where the nv30/nv40 isa is documented.

Signed-off-by: Samuel Pitoiset <506e97eed81d9e59d22f4c73fb51123bb62b4a30@gmail.com>
Reviewed-by: Ilia Mirkin <bcbbb7aa705ec3a5fc5824c01a845186c3d62fca@alum.mit.edu>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler