net: wan: framer: Add missing static inline qualifiers

Compilation with CONFIG_GENERIC_FRAMER disabled lead to the following
warnings:
framer.h:184:16: warning: no previous prototype for function 'framer_get' [-Wmissing-prototypes]
184 | struct framer *framer_get(struct device *dev, const char *con_id)
framer.h:184:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
184 | struct framer *framer_get(struct device *dev, const char *con_id)
framer.h:189:6: warning: no previous prototype for function 'framer_put' [-Wmissing-prototypes]
189 | void framer_put(struct device *dev, struct framer *framer)
framer.h:189:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
189 | void framer_put(struct device *dev, struct framer *framer)

Add missing 'static inline' qualifiers for these functions.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202403241110.hfJqeJRu-lkp@intel.com/
Fixes: 82c944d05b1a ("net: wan: Add framer framework support")
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>