docs: ABI: Fix "firwmare" to "firmware"

Fix misspelling reported by codespell

Signed-off-by: Sumanth Gavini <sumanth.gavini@yahoo.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://patch.msgid.link/20250517110332.1289718-1-sumanth.gavini@yahoo.com


Signed-off-by: Dave Jiang <dave.jiang@intel.com>