ts2020: fix compilation on i386

drivers/built-in.o: In function `ts2020_read_signal_strength':
ts2020.c:(.text+0x298ff94): undefined reference to `__divdi3'
ts2020.c:(.text+0x298ffd4): undefined reference to `__divdi3'
ts2020.c:(.text+0x298fffd): undefined reference to `__divdi3'
Makefile:921: recipe for target 'vmlinux' failed

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>