mce-amd-smca: update smca_hwid to use smca_bank_types

mce-amd-smca: update smca_hwid to use smca_bank_types

bank_type is used as smca_bank_types everywhere, there's no point in
declaring it as unsigned int. It also upsets covscan:

	3. rasdaemon-0.6.7/mce-amd-smca.c:914: assignment: Assigning: "bank_type" = "s_hwid->bank_type".
	7. rasdaemon-0.6.7/mce-amd-smca.c:926: cond_at_most: Checking "bank_type >= 64U" implies that "bank_type" and "s_hwid->bank_type" may be up to 63 on the false branch.
	14. rasdaemon-0.6.7/mce-amd-smca.c:942: overrun-local: Overrunning array "smca_mce_descs" of 38 16-byte elements at element index 63 (byte offset 1023) using index "bank_type" (which evaluates to 63).
	#   940|        /* Only print the descriptor of valid extended error code */
	#   941|        if (xec < smca_mce_descs[bank_type].num_descs)
	#   942|->              mce_snprintf(e->mcastatus_msg,
	#   943|                             "%s. Ext Err Code: %d",
	#   944|                             smca_mce_descs[bank_type].descs[xec],

Signed-off-by: Aristeu Rozanski <arozansk@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>