reset: ti_syscon: Rename TI_SYSCON_RESET to RESET_TI_SYSCON

Rename the current Kconfig name used for the TI SYSCON Reset
driver from TI_SYSCON_RESET to RESET_TI_SYSCON to match the
convention used for all the reset drivers present at the
base reset folder.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>