ARM: dts: dra7-evm: Fix spi1 mux documentation

While auditing the various pin ctrl configurations using the following
command:
grep PIN_ arch/arm/boot/dts/dra7-evm.dts|(while read line;
do
	v=`echo "$line" | sed -e "s/\s\s*/|/g" | cut -d '|' -f1 |
		cut -d 'x' -f2|tr [a-z] [A-Z]`;
	HEX=`echo "obase=16;ibase=16;4A003400+$v"| bc`;
	echo "$HEX ===> $line";
done)
against DRA75x/74x NDA TRM revision S(SPRUHI2S August 2014),
documentation errors were found for spi1 pinctrl. Fix the same.

Fixes: 6e58b8f1

 ("ARM: dts: DRA7: Add the dts files for dra7 SoC and dra7-evm board")
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>