ARM: dts: keystone-k2g-evm: Fix botched up merge

spi1 and ecap0 pinmuxes ended up under root node instead of k2g_pinctrl
node. Fix this by moving them under k2g_pinctrl node.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>