microblaze: add arch_print_bdinfo() implementation

Allow bdinfo command to print icache/dcache information:
U-Boot-mONStR> bdinfo
boot_params = 0x00000000
DRAM bank = 0x00000000
-> start = 0x04000000
-> size = 0x04000000
flashstart = 0x00000000
flashsize = 0x00000000
flashoffset = 0x00000000
baudrate = 9600 bps
relocaddr = 0x07f76000
reloc off = 0x02f76000
Build = 32-bit
current eth = unknown
ethaddr = (not set)
IP addr = <NULL>
fdt_blob = 0x07fec7e0
new_fdt = 0x00000000
fdt_size = 0x00000000
lmb_dump_all:
memory.cnt = 0x1
memory[0] [0x4000000-0x7ffffff], 0x04000000 bytes flags: 0
reserved.cnt = 0x1
reserved[0] [0x7e94b8c-0x7ffffff], 0x0016b474 bytes flags: 0
devicetree = embed
icache = 32 KiB
icache line = 4 Bytes
dcache = 32 KiB
dcache line = 4 Bytes

Signed-off-by: Ovidiu Panait <ovpanait@gmail.com>
Link: https://lore.kernel.org/r/20220829170205.1274484-4-ovpanait@gmail.com
Signed-off-by: Michal Simek <michal.simek@amd.com>