Add support for identifying and reporting basic info for (U)EFI Capsules

Identify the GUIDs for EFI Capsule formats, both v0.9, v2 and UEFI
versions, which are essentially the same for what gets reported.

src/binwalk/magic/firmware

@@ -497,6 +497,42 @@
 
 16    string        \xd9\x54\x93\x7a\x68\x04\x4a\x44\x81\xce\x0b\xf6\x17\xd8\x90\xdf    UEFI PI firmware volume
 
+# http://www.intel.com/content/www/us/en/architecture-and-technology/\
+# unified-extensible-firmware-interface/efi-capsule-specification.html
+# GUID: 3B6686BD-0D76-4030-B70E-B5519E2FC5A0
+
+0       lelong     0x3b6686bd        EFI Capsule v0.9
+>4      leshort    0xd76
+>6      leshort    0x4030
+>8      string     \xb7\x0e\xb5\x51\x9e\x2f\xc5\xa0
+>16     lelong     x                 \b, header size: %d
+>20     lelong     x                 \b, flags: 0x%.8X
+>24     lelong     x                 \b, capsule size: %d
+
+# EFI2 format, based on https://gist.github.com/XVilka/8163272
+# GUID: 4A3CA68B-7723-48FB-803D-578CC1FEC44D
+
+0       lelong     0x4a3ca68b        EFI Capsule v2
+>4      leshort    0x7723
+>6      leshort    0x48fb
+>8      string     \x57\x8c\xc1\xfe\xc4\x4d
+>16     lelong     x                 \b, header size: %d
+>20     lelong     x                 \b, flags: 0x%.8X
+>24     lelong     x                 \b, capsule size: %d
+
+# UEFI format
+# http://www.uefi.org/sites/default/files/resources/UEFI%202_5.pdf
+# GUID: 539182B9-ABB5-4391-B69A-E3A943F72FCC
+
+0       lelong     0x539182b9        UEFI Capsule
+>4      leshort    0xabb5
+>6      leshort    0x869a
+>8      string     \xe3\xa9\x43\xf7\x2f\xcc
+>16     lelong     x                 \b, header size: %d
+>20     lelong     x                 \b, flags: 0x%.8X
+>24     lelong     x                 \b, capsule size: %d
+
+
 # http://android.stackexchange.com/questions/23357/\
 # is-there-a-way-to-look-inside-and-modify-an-adb-backup-created-file/\
 # 23608#23608