mips: check for dsp presence only once before save/restore

{save,restore}_dsp() internally checks if the cpu has dsp support.
Therefore, explicit check is not required before calling them in
{save,restore}_processor_state()

Signed-off-by: Aurabindo Jayamohanan <mail@aurabindo.in>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: ralf@linux-mips.org
Cc: jhogan@kernel.org
Cc: alexios.zavras@intel.com
Cc: gregkh@linuxfoundation.org
Cc: armijn@tjaldur.nl
Cc: allison@lohutok.net
Cc: tglx@linutronix.de
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org