input: ft5x06_ts: check vendor id before upgrade FT firmware

Upgrade the firmware only if same vendor id is found both in existing
fw and new fw to be upgraded.

  This patch is propagated from 3.10 kernel
    commit: a8bf8790e0e416059448ec0b63f5148c6a16211a
    input: ft5x06_ts: check vendor id before upgrade FT firmware

Change-Id: Idfc50da45891a1475ac6b35d80c7d725607cbf81
Signed-off-by: Mao Li <maol@codeaurora.org>