ipq806x: fix pvs1_bin voltage in ipq8065 DT

Fixing pvs1 bin voltage as found in GPL tarball and Qualcomm SDK.

Also adjusting smb208_s2a/b minimum voltage to reflect lowest value in pvs table.

Current ipq8065 devices in LEDE choose (based on eFuse data) pvs bin n4, that has
correct values in DT, but in future a new device may choose n1 or n6.

Without this change n1 is semi-correct and n6 is not available, because OPP driver
disregards bins with voltage values that regulator cannot supply.

Signed-off-by: Pavel Kubelun <be.dissent@gmail.com>