bus/ifpga: fix const pointer in device name parsing

bus/ifpga: fix const pointer in device name parsing

With latest glibc (Fedora Rawhide):
../drivers/bus/ifpga/ifpga_bus.c: In function 'ifpga_parse':
../drivers/bus/ifpga/ifpga_bus.c:479:12: warning: assignment discards
	'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
  479 |         c1 = strchr(name, '|');
      |            ^

Fixes: 05fa3d4a6539 ("bus/ifpga: add Intel FPGA bus library")
Cc: stable@dpdk.org
Signed-off-by: David Marchand <david.marchand@redhat.com>