ARM: 6031/1: fix Thumb-2 decompressor

98e12b5a ("ARM: Fix decompressor's kernel size estimation for
ROM=y") broke the Thumb-2 decompressor because it added an entry in the
LC0 table but didn't adjust the offset the Thumb-2 code uses to load the
SP from that table.  Fix it.

Cc: stable <stable@kernel.org>
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>