tools: checkpatch.pl from Linux added to tools

Added from Linux - commit 30ecad51849ae132dc6ef6ddb62d499c7257515b

Include config file to ignore common false-positives

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Cc: Joe Hershberger <joe.hershberger@gmail.com>
Cc: Wolfgang Denk <wd@denx.de>

.checkpatch.conf

+# Not Linux, so don't expect a Linux tree.
+--no-tree
+
+# Temporary for false positive in checkpatch
+--ignore COMPLEX_MACRO
+
+# For CONFIG_SYS_I2C_NOPROBES
+--ignore MULTISTATEMENT_MACRO_USE_DO_WHILE
+
+# For simple_strtoul
+--ignore CONSIDER_KSTRTO
+
+# For min/max
+--ignore MINMAX