Removing MK{GCCCMDS,BINUTILS}=yes in image scripts

Removing MK{GCCCMDS,BINUTILS}=yes in image scripts

MKGCCCMDS=yes and MKBINUTILS=yes where added on the build command line
while they should have been left to the developer's discretion.

To build and install binutils and gcc do the following:

 $ BUILDVARS='-V MKBINUTILS=yes -V MKGCC=yes -V MKGCCCMDS=yes' \
    ./releasetools/arm_sdimage.sh
or

 $ BUILDVARS='-V MKBINUTILS=yes -V MKGCC=yes -V MKGCCCMDS=yes' \
    ./releasetools/x86_hdimage.sh

Change-Id: Icb46a3422f527747768fa107d14fc19ff3ac0a63