mips: ralink: make SOC_MT7621 select PINCTRL_MT7621 and fix help section

The dt-binding of the MT7621 SoC uses the pinctrl driver. Therefore, have
this driver selected by default.

The help section for SOC_MT7621 exceeds 80 columns which is the preferred
limit of a single line. A tab character is 8 columns. Rearrange the text
accordingly.
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/ralink/Kconfig

@@ -54,10 +54,11 @@ choice
 		select HAVE_PCI
 		select PCI_DRIVERS_GENERIC
 		select SOC_BUS
+		select PINCTRL_MT7621
 
 		help
-		  The MT7621 system-on-a-chip includes an 880 MHz MIPS1004Kc dual-core CPU,
-		  a 5-port 10/100/1000 switch/PHY and one RGMII.
+		  The MT7621 system-on-a-chip includes an 880 MHz MIPS1004Kc
+		  dual-core CPU, a 5-port 10/100/1000 switch/PHY and one RGMII.
 endchoice
 
 choice