Allow compatibility with 'old' Touchscreens (Linux < 3.1)

BOARD_USE_LEGACY_TOUCHSCREEN := true in your BoardConfig.mk

Support the Multitouch, 10-points tested on the qtouch (Defy/Droid)

Remember to add the new idc file required for the touchscreen/keypad
Example: /system/usr/idc/qtouch-touchscreen.idc

Change-Id: I62f8b36350784ec6ba73f4a2d942f441fe710ae3
Signed-off-by: Tanguy Pruvot <tanguy.pruvot@gmail.com>