ARM: Kconfig: remove useless "default n"

The default for Kconfig options is always n, so there's no need to
explicitly state a "n" default.

Acked-by: Tony Lindgren <[e-mail]>
Acked-by: Robert Jarzmik <[e-mail]>
Signed-off-by: Russell King <[e-mail]>

arch/arm/Kconfig

···
 config PARAVIRT_TIME_ACCOUNTING
 	bool "Paravirtual steal time accounting"
 	select PARAVIRT
-	default n
 	help
 	  Select this option to enable fine granularity task steal time
 	  accounting. Time spent executing other tasks in parallel with

arch/arm/mach-omap2/Kconfig

···
 config OMAP3_SDRC_AC_TIMING
 	bool "Enable SDRC AC timing register changes"
 	depends on ARCH_OMAP3
-	default n
 	help
 	  If you know that none of your system initiators will attempt to
 	  access SDRAM during CORE DVFS, select Y here.  This should boost

arch/arm/mach-pxa/Kconfig

···
 config TOSA_USE_EXT_KEYCODES
 	bool "Tosa keyboard: use extended keycodes"
 	depends on MACH_TOSA
-	default n
 	help
 	  Say Y here to enable the tosa keyboard driver to generate extended
 	  (>= 127) keycodes. Be aware, that they can't be correctly interpreted

arch/arm/plat-omap/Kconfig

···
 config OMAP3_L2_AUX_SECURE_SAVE_RESTORE
 	bool "OMAP3 HS/EMU save and restore for L2 AUX control register"
 	depends on ARCH_OMAP3 && PM
-	default n
 	help
 	  Without this option, L2 Auxiliary control register contents are
 	  lost during off-mode entry on HS/EMU devices. This feature