meta-ibm: witherspoon: fans: drop unused variable

meta-phosphor dropped support for native class config recipes and uses
target class config recipes by default.  Drop the reference to
PHOSPHOR_FAN_CONFIG_USE_NATIVE_SYSROOT as it is no longer used in
meta-phosphor.

Change-Id: I5a259d7a63b70468f6301ca1f3f0487142d5d70c
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
1 file changed