Backport #973 from trunk:
Don't allow to specify an ABI for ARM EABI builds: the ABI is implied by the fact we're building for EABI.

/branches/1.2/arch/arm/functions | 19 3 16 0 +++----------------
/branches/1.2/arch/arm/config.in | 9 6 3 0 ++++++---
2 files changed, 9 insertions(+), 19 deletions(-)

# Compute powerpc-specific values

CT_DoArchValues () {

    # The architecture part of the tuple:

    CT_TARGET_ARCH="${CT_ARCH}"

    # The kernel ARCH:

    CT_KERNEL_ARCH=powerpc

}