buildgcc: Rename armv7-a-eabi compiler to arm-eabi

The compiler really supports a whole line of ARM CPUs, not just
ARMv7a:
arm-eabi-gcc: note: valid arguments to '-march=' are: armv2 armv2a
   armv3 armv3m armv4 armv4t armv5 armv5e armv5t armv5te armv6 armv6-m
   armv6j armv6k armv6s-m armv6t2 armv6z armv6zk armv7 armv7-a armv7-m
   armv7-r armv7e-m armv7ve armv8-a armv8-a+crc iwmmxt iwmmxt2 native
So let's reflect this in the cross compiler name.

Change-Id: I717760d80954655b2de9ae019b813d81e9a75762
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: https://review.coreboot.org/13515
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2 files changed