MIPS: xburst/start.S: save relocation address in s2 register

Synchronize the code with mips{32,64}/start.S, in order to
allow further unifications.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: Daniel Schwierzeck <daniel.schwierzeck@googlemail.com>
1 file changed