cmd: efidebug: add memmap command

cmd: efidebug: add memmap command

"memmap" command prints uefi-specific memory map information.
=> efi memmap
Type             Start            End              Attributes
================ ================ ================ ==========
CONVENTIONAL     0000000040000000-000000007de27000 WB
RUNTIME DATA     000000007de27000-000000007de28000 WB|RT
RESERVED         000000007de28000-000000007de2a000 WB
RUNTIME DATA     000000007de2a000-000000007de2b000 WB|RT
RESERVED         000000007de2b000-000000007de2c000 WB
RUNTIME DATA     000000007de2c000-000000007de2d000 WB|RT
LOADER DATA      000000007de2d000-000000007ff37000 WB
RUNTIME CODE     000000007ff37000-000000007ff38000 WB|RT
LOADER DATA      000000007ff38000-0000000080000000 WB

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>