MIPS: Malta: EVA: Rename 'eva_entry' to 'platform_eva_init'

MIPS: Malta: EVA: Rename 'eva_entry' to 'platform_eva_init'

Rename 'eva_entry' to 'platform_eva_init' as required by the new
'eva_init' macro in the eva.h header. Since this macro is now used
in a platform dependent way, it must not depend on its caller so move
the t1 register initialization inside this macro. Also set the .reorder
assembler option in case the caller may have previously set .noreorder.
This may allow a few assembler optimizations. Finally include missing
headers and document the register usage for this macro.

Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: http://patchwork.linux-mips.org/patch/7423/
Signed-off-by: James Hogan <james.hogan@imgtec.com>