[PATCH] Fix process crash in 2.4 on attempt to use FPU on MIPS32

If there's built-in FPU in a MIPS32 CPU the first time the process tries
to use it, the kernel should crash with "reserved instruction" -- CPU will try
to execute 'dmtc1' which is a MIPS64 only insn. _init_fpu() was apprently blindly copied form arch/mips64/... :-)

Since this occured with GXemul recently resending this 1.5 year old patch.

Signed-off-by: Sergei Shtylyov <redacted>