ARM: dts: am335x-bone-common: Fix mmc0 Write Protect

Mainline Commit b74c2b21 added the pinmux
settings for mmc1, however this pin (0x9a0) is routed to P9_42 on the cape
header. Thus any BeagleBone cape that utilizes P9_42 triggers mmc0's Write
Protect.

Fixes: b74c2b21 ("ARM: dts: am33xx: Add pinmux data for mmc1 in
am335x-evm, evmsk and beaglebone")
Signed-off-by: Robert Nelson <robertcnelson@gmail.com>
CC: Faiz Abbas <faiz_abbas@ti.com>
CC: Tony Lindgren <tony@atomide.com>
CC: Jason Kridner <jkridner@beagleboard.org>
CC: Drew Fustini <drew@beagleboard.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>