firmware: tuners/xc2028: prepare for FIRMWARE_NAME_MAX removal

We're going to remove the FIRMWARE_NAME_MAX definition in order to avoid any
firmware name length restriction.
This patch gets rid of the xc2028 FIRMWARE_NAME_MAX reference.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Michel Ludwig <michel.ludwig@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>