phy: exynos5-usbdrd: fix definition of EXYNOS5_FSEL_26MHZ

Using 0x82 seems odd, where everything else is just a sequence.

On E850, this macro isn't used (as a register value), only to assign
its value to the 'extrefclk' variable, which is otherwise unused on
that platform. Older platforms don't appear to support 26MHz in the
first place (since this macro was added for E850).

Furthermore, the downstream driver uses 0x82 to denote
USBPHY_REFCLK_DIFF_26MHZ (whatever that means exactly), but for all the
other values we match downstream's non-DIFF macros.

Update to avoid confusion. No functional change intended.

Signed-off-by: André Draszik <andre.draszik@linaro.org>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Link: https://lore.kernel.org/r/20240507-samsung-usb-phy-fixes-v1-4-4ccba5afa7cc@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>