KW41Z: Avoid using TARGET_NXP macro

Having Freescale and NXP macro causes compile from both
TARGET_Freescale and TARGET_NXP HAL folders.

Signed-off-by: Mahesh Mahadevan <[email protected]>

Author: mmahadevan108

features/nanostack/targets/TARGET_NXP/TARGET_KW41Z/NanostackRfPhyKw41z.cpp renamed to features/nanostack/targets/TARGET_Freescale/TARGET_KW41Z/NanostackRfPhyKw41z.cpp

@@ -696,8 +696,7 @@
             "MCUXpresso_MCUS",
             "KSDK2_MCUS",
             "FRDM",
-            "FRAMEWORK_5_3_3",
-            "NXP"
+            "FRAMEWORK_5_3_3"
         ],
         "is_disk_virtual": true,
         "macros": [