package/tpm2-tools: fix build with gcc 4.8

package/tpm2-tools: fix build with gcc 4.8

Fix the following build failure with gcc 4.8 raised since bump to
version 4.3.2 in commit	91aa6efa8588bf7617cc4a640eb55052b524ceb7:

lib/tpm2_eventlog_yaml.c: In function 'yaml_uefi_var_unicodename':
lib/tpm2_eventlog_yaml.c:130:5: error: 'for' loop initial declarations are only allowed in C99 mode
     for(size_t i = 0; i < data->UnicodeNameLength; ++i, tmp += ret) {
     ^
lib/tpm2_eventlog_yaml.c:130:5: note: use option -std=c99 or -std=gnu99 to compile your code
lib/tpm2_eventlog_yaml.c: In function 'yaml_specid_algs':
lib/tpm2_eventlog_yaml.c:335:5: error: 'for' loop initial declarations are only allowed in C99 mode
     for (size_t i = 0; i < count; ++i, ++alg) {
     ^

Fixes:
 - http://autobuild.buildroot.org/results/018c75cfbb34006c0bca52dcc255ad6f9cc43b77

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>