uboot-phytec

ARM: mx6: Enable Thumb build for SPL

Building the SPL in Thumb mode saves roughly 30% in size of the
resulting SPL binary. As the size of SPL it limited on the MX6,
this helps a lot.

Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Tim Harvey <tharvey@gateworks.com>