usb_pd_protocol: Only print TCPC info if available
usb_pd_protocol: Only print TCPC info if available

tcpm_get_chip_info does not modify the parameter info if the
function is not implemented on the given chip.

This has a interesting side effect on Kevin, where, for whatever
reason, info's value ends up being 1, and causes unaligned access
exception:

[0.039 TCPC p0 init ready]

=== PROCESS EXCEPTION: 06 ====== xPSR: 61000000 ===
r0 :00000000 r1 :28000000 r2 :00000001 r3 :00000000
r4 :00000000 r5 :00000000 r6 :00000000 r7 :00000000
r8 :200c60f4 r9 :00000000 r10:100c0c3c r11:00000000
r12:200c52ed sp :200c5320 lr :100a9c71 pc :100abd5a
Unaligned
mmfs = 1000000, shcsr = 70008, hfsr = 0, dfsr = 0

BRANCH=none
BUG=none
TEST=On ToT make BOARD=kevin -j; flash, kevin boots

Change-Id: Ie7e758d5fb8c31180f36b073b635e54cc720a8a0
Signed-off-by: Nicolas Boichat <f3daba1cdc403799935674d3cd4b0e5bd1804232@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1073179
Reviewed-by: Vincent Palatin <70a9964ec8fd10b0b08fcc8623c2add25ddf99ac@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec