pinctrl: pistachio: fix mfio84-89 function description and pinmux.

mfio 84 to 89 are described wrongly, fix it to describe
the right pin and add them to right pin-mux group.

The correct order is:
	pll1_lock => mips_pll	-- MFIO_83
	pll2_lock => audio_pll	-- MFIO_84
	pll3_lock => rpu_v_pll	-- MFIO_85
	pll4_lock => rpu_l_pll	-- MFIO_86
	pll5_lock => sys_pll	-- MFIO_87
	pll6_lock => wifi_pll	-- MFIO_88
	pll7_lock => bt_pll	-- MFIO_89

Cc: linux-gpio@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: James Hartley <James.Hartley@imgtec.com>
Cc: <stable@vger.kernel.org> # v4.2+
Fixes: cefc03e5("pinctrl: Add Pistachio SoC pin control driver")
Signed-off-by: Govindraj Raja <Govindraj.Raja@imgtec.com>
Acked-by: Andrew Bresticker <abrestic@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>