Squashed commit of the following:
boards/arm/s32k1xx/s32k148evb: Correct linker scripts for the S32K148, Update README files, Hook eht S32K148EVB into the configuration and build system.
arm/s32k1xx/s32k148evb: Verify core and peripheral clocking. It is the same as the S32K146EVB. Fixed one-too-many copy-paste error in both.
boards/arm/s32k1xx/s32k148evb: Correct LED and button pin number for the S32K148EVB.
boards/arm/s32k1xx/s32k148evb: Change all occurrences of 146 to 148.
boards/arm/s32k1xx/s32k148evb: Initial S32K148EVB. Initial commit is just clone of S32K146EVB with file name changes