octeontx2-af: fix build regression without CONFIG_DCB

octeontx2-af: fix build regression without CONFIG_DCB

When DCB is disabled, the pfc_en struct member cannot be accessed:

drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c: In function 'otx2_is_pfc_enabled':
drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c:22:48: error: 'struct otx2_nic' has no member named 'pfc_en'
   22 |         return IS_ENABLED(CONFIG_DCB) && !!pfvf->pfc_en;
      |                                                ^~
drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c: In function 'otx2_nix_config_bp':
drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c:1755:33: error: 'IEEE_8021QAZ_MAX_TCS' undeclared (first use in this function)
 1755 |                 req->chan_cnt = IEEE_8021QAZ_MAX_TCS;
      |                                 ^~~~~~~~~~~~~~~~~~~~

Move the member out of the #ifdef block to avoid putting back another
check in the source file and add the missing include file unconditionally.

Fixes: a7ef63dbd588 ("octeontx2-af: Disable backpressure between CPT and NIX")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20241213083228.2645757-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>