[sw/dif_pwrmgr] Power Manager DIF Library Header

This change introduces the header of the power manager DIF library that
defines its public interface.

Signed-off-by: Alphan Ulusoy <alphan@google.com>
diff --git a/meson.build b/meson.build
index b3f2eec..3213193 100644
--- a/meson.build
+++ b/meson.build
@@ -131,6 +131,7 @@
 hw_ip_rv_timer_reg_h = gen_hw_hdr.process('hw/ip/rv_timer/data/rv_timer.hjson')
 hw_ip_uart_reg_h = gen_hw_hdr.process('hw/ip/uart/data/uart.hjson')
 hw_ip_usbdev_reg_h = gen_hw_hdr.process('hw/ip/usbdev/data/usbdev.hjson')
+hw_ip_pwrmgr_reg_h = gen_hw_hdr.process('hw/top_earlgrey/ip/pwrmgr/data/autogen/pwrmgr.hjson')
 hw_top_earlgrey_pinmux_reg_h = gen_hw_hdr.process('hw/top_earlgrey/ip/pinmux/data/autogen/pinmux.hjson')
 hw_top_earlgrey_rv_plic_reg_h = gen_hw_hdr.process('hw/top_earlgrey/ip/rv_plic/data/autogen/rv_plic.hjson')