.gitignore: added couple of usual file types

Signed-off-by: Ong Boon Leong <elvinongbl@gmail.com>
script: bcross-compile-linux-check: initial script

This script is used to automatically cross-compile Linux kernel branch
and output any build error under $LOG_DIR define.

Currently, it supports:
  ARCH=arm     CROSS_COMPILE=arm-linux-gnueabi-  make
  ARCH=arm64   CROSS_COMPILE=arm64-linux-gnu-    make
  ARCH=powerpc CROSS_COMPILE=powerpc-linux-gnu-  make

Signed-off-by: Ong Boon Leong <elvinongbl@gmail.com>