ARM: nomadik: disable chrystals in top level board files

Do not force disable the chrystals in the SoC file, this is
per-board dependent.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/boot/dts/ste-nomadik-stn8815.dtsi

@@ -182,8 +182,6 @@ i2c2_default_cfg {
 	src: src@101e0000 {
 		compatible = "stericsson,nomadik-src";
 		reg = <0x101e0000 0x1000>;
-		disable-sxtalo;
-		disable-mxtalo;
 
 		/*
 		 * MXTAL "Main Chrystal" is a chrystal oscillator @19.2 MHz